The National Highway Traffic Safety Administration (NHTSA) published an Advance Notice of Proposed Rulemaking (ANPRM) to update the Federal Motor Vehicle Safety Standard (FMVSS) 207. Part of the ANPRM is to assess the merit of conducting quasi static body block seat pull tests and conducting FMVSS 301 rear crash tests at 80 km/h or higher with a 95th percentile ATD lap-shoulder belted in the front seats and limiting seatback deflection to 15 to 25 degrees. Prior to updating regulations, it is important to understand the seating design history and implications. This study was conducted to provide a historical background on seat design and performance using literature and test data. One objective was to first define the terminology used to describe occupant kinematics in rear crashes. Secondly, seat design evolution is then discussed. Third, test methods and test results were summarized, and fourth, the field performance are synopsized and discussed with respect to 2nd row occupant

Parenteau, Chantal, Burnett, Roger, Davidson, Russell

Real-Time PMV Thermal Comfort Index Observer Based on Artificial Neural Networks for Infrared Heating Panel Control

2025-01-8139

04/01/2025

Improving electric vehicles’ range can be achieved by integrating infrared heating panels (IRPs) into the existing Heating Ventilation and Air-Conditioning system to reduce battery energy consumption while maintaining thermal comfort. Localized comfort control enabled by IRPs is facilitated by thermal comfort index feedback to the control strategy, such as the well-known Predicted Mean Vote (PMV). PMV is obtained by solving nonlinear equations iteratively, which is computationally expensive for vehicle control units and may not be feasible for real-time control. This paper presents the design of real-time capable thermal comfort observer based on feedforward artificial neural network (ANN), utilized for estimating the local PMV extended with IRP radiative heating effects. The vehicle under consideration is equipped with 12 heating panels (zones) organized into six controller clusters that rely on the average PMV feedback from its respective zone provided by a dedicated ANN. Each of six

Cvok, Ivan, Yerramilli-Rao, Isha, Miklauzic, Filip

Emissions Savings from Efficient Mobile Air-Conditioning (MAC) Systems in Passenger Vehicles

2025-01-8156

04/01/2025

Mobile Air-Conditioning (MAC) systems are a substantial source of energy consumption and CO₂ emissions in passenger vehicles, particularly for electrified vehicles under real-world operating conditions. Enhancing the efficiency of such systems is imperative to achieving greater energy efficiency and maintaining occupants’ comfort. In recognition of their significance, MAC systems can be classified as eco-innovative technologies under EU Regulation 2019/631, effective from 2025. This study lays the groundwork for a methodology to calculate CO₂ savings from eco-innovative MAC systems in passenger cars. The approach compares CO₂ emissions between baseline and eco-innovative vehicles under active and inactive MAC systems. Literature-derived indicative ambient conditions are applied to reflect realistic MAC usage scenarios in Europe. The testing protocol follows the WLTP procedure under controlled ambient conditions, including temperature, humidity, and solar irradiation, which can either

Di Pierro, Giuseppe, Currò, Davide, Gil-Sayas, Susana, Fontaras, Georgios

A Reconfigurable Backrest Surface for Investigating Preferred Seat Configurations

2025-01-8611

04/01/2025

A reconfigurable experimental seat is useful for seating comfort research and allows researchers to investigate the effects of seat parameters and to propose quantitative guidelines for improving seat comfort. Since 2017, Gustave Eiffel University has such an experimental seat which allows us to carry out parametric studies on the geometric dimensions of a seat and to understand the role of the contact force, particularly that in shear force. Equipped with force and positioning sensors, all contact forces and seat position can be measured. More specifically, it is equipped on the seat with a matrix of 52 cylinders, each adjustable in height and each equipped with a three-axis force sensor. These cylinders make it possible to vary the contact surface of seat pan and measure the distribution of contact forces. More recently, a new system with a matrix of 263 hydraulic cylinders was designed and manufactured to better study the comfort of the backrest in replacement of the three-support

Wang, Xuguang, Beurier, Georges

Occupant Responses in High-Speed Rear Sled Tests: Focus of Initial Position, Seat Strength and ATD Size

2025-01-8731

04/01/2025

The National Highway Safety Administration (NHTSA) recently published an Advanced Notice of Proposed Rulemaking (ANPRM) to evaluate seat performance in rear impacts [1]. The ANPRM was issued partially in response to two petitions requesting an increase in seatback strength requirements and high-speed testing with various size Anthropometric Test Devices (ATDs). To better understand the effect of these requests, this study evaluates ATD responses with two high-speed rear sled conditions, three occupant sizes and various seat designs. Seat designs varied from modern conventional seats with yielding properties to stronger and stiffer seats represented by seat integrated restraint (SIR) designs, and rigidized SIR seats. Twenty-four rear sled tests were analyzed. The tests were matched by crash severity, seat designs (strength), ATD sizes and initial postures (nominal/in-position, leaned forward and leaned outboard). The test data and videos were reviewed to identify time coinciding with

Parenteau, Chantal, Burnett, Roger

Aeroacoustic Noise Prediction of Passenger Car HVAC by Using CFD and Validation with Test Result

2025-01-8629

04/01/2025

The advancement of automotive industry demand compact size of HVAC with better cabin comfort. To achieve this, HVAC has to be optimized in all the aspects such as in shape & size, thermal comfort as well as in noise comfort. from an HVAC perspective, aeroacoustics noise is more significant due to its intensity at higher speeds and frequencies. Since HVAC is mounted inside the cabin, noise can transfer directly inside cabin. To avoid this, noise reduction or noise controlling is of very important. This is possible with HVAC design and simulation at the initial level and acoustic prediction after the CFD/CAA analysis. The present paper describes the aeroacoustic simulation of one of the HVAC to predict the noise during face mode. For that, 1-D simulation has been done initially to find the porosity of heat exchangers and coupled with a CFD solver. STAR CCM+ software is used for the CFD analysis. Transient simulation is performed with compressible fluid using a moving mesh approach. To

Kame, Shubham, Parayil, Paulson, Goel, Arunkumar

A Co-Simulation Methodology for Predicting Occupant Thermal Comfort for Cabin Cooldown and Warmup Scenarios

2025-01-8188

04/01/2025

Achieving and maintaining thermal comfort for vehicle cabin cool down and warm up is a challenging task. Keeping the passenger comfortable in all driving scenarios needs a properly sized system. Predicting thermal comfort in a virtual environment consisting of thermal system and vehicle cabin gives us the opportunity to size the system components to maintain thermal comfort. These studies could then be extended to develop comfort-based control strategies that help us achieve a system optimized for performance. The present study focuses on developing a co-simulation methodology for predicting thermal comfort in a vehicle for hot and cold ambient conditions. Key to proper system sizing would be to capture the cabin thermal loads accurately. Traditionally, either a 1D or 3D cabin model is used for assessment of thermal comfort. Both these cabin models have their own applications and limitations. A 1D-3D cabin model along with the developed co-simulation methodology in this work addresses

Balasubramanian, Sudharsan, Natarajan, Shankar

Battery Thermal Management System for PHEV by using Air Conditioning Heater System

2025-01-8172

04/01/2025

Toyota Motor Corporation pursuing an omnidirectional strategy that includes battery electric vehicle (BEV), plug-in hybrid electric vehicle (PHEV), and fuel cell electric vehicle (FCEV) to accelerate electrification. One of the technical challenges with our xEV batteries which feature good degradation resistance and long battery life, is that regenerative braking cannot be fully effective due to the decrease in regenerative power in some situations, such as low battery temperature. For the electrified vehicles with an internal combustion engine such as PHEVs, the solution has been running the engine to increase deceleration through engine braking during coasting. PHEVs are expected to extend their cruising range and enhance EV driving experience as "Practical BEVs". While increasing battery capacity and enhancing convenience, the restrictions on EV driving opportunity due to low battery temperature may negatively affect PHEV’s appealing. As an alternative, introducing a battery heater

Hoshino, Yu

Control Trajectory Optimization of Electric Vehicle Heat Pump-Based Cabin Heating System

2025-01-8144

04/01/2025

Optimal control of battery electric vehicle thermal management systems is essential for maximizi ng the driving range in extreme weather conditions. Vehicles equipped with advanced heating, ventilation and air-conditioning (HVAC) systems based on heat pumps with secondary coolant loops are more challenging to control due to actuator redundancy and increased thermal inertia. This paper presents the dynamic programming (DP)-based offline control trajectory optimization of heat pump-based HVAC aimed at maximizing thermal comfort and energy efficiency. Besides deriving benchmark results, the goal of trajectory optimization is to gain insights for practical hierarchical control strategy modifications to further improve real-time controllers’ performance. DP optimizes cabin inlet air temperature and flow rate to set the trade-off between thermal comfort and energy efficiency while considering the nonlinear dynamics and operating limits of HVAC system in addition to typically considered cabin

Cvok, Ivan, Deur, Josko

A Novel Co-Simulation Framework for Optimizing Human Thermal Comfort and Energy Consumption in a Vehicle

2025-01-8191

04/01/2025

A major portion of the energy consumed in a vehicle is spent on keeping the occupants thermally comfortable in all environmental conditions when the heating, ventilation, and air-conditioning (HVAC) system is turned on. Maintaining the thermal comfort of a passenger is critical in terms of fuel consumption and emission for internal combustion engine (ICE) vehicles. In electrified vehicles, where range is of major concern, this gains further-more importance. SC03 is a test defined by the US Environmental Protection Agency (EPA) to measure tailpipe emissions and fuel economy of passenger cars with the air-conditioner on. The current study would focus on this drive cycle on an ICE vehicle. The co-simulation framework would include a 1D thermal system model, associated thermal controls, a vehicle cabin model, and a human thermal model. 1D model will be predicting the energy consumption via compressor power, refrigerant pressure and temperature across the loop, component heat rejection, etc

Natarajan, Shankar, Balasubramanian, Sudharsan

Coordinated motor speed control design for seat systems

2025-01-8069

04/01/2025

Automotive seating systems have become increasingly sophisticated, providing consumers with more flexible configurations and comfort functionalities. Traditional power seating, which relied on a few motors to adjust the seat position, has evolved into more technically advanced reconfigurable systems equipped with additional feedback sensors and actuators. These advancements include features such as Easy Entry, Zero Gravity, Stadium Swivel, IP Nesting, Auto Lumbar/Bolster Adjustment and Power Long Rails. All the features indicate that the overall control of seating systems now resembles robotic arm control or multi-body control, involving numerous coordinated movements. In this paper, we propose a novel control strategy for the coordinated speed control of multiple motors. Unlike traditional seating controls, which typically use direct switches or open-loop systems, we introduce a feedback approach that incorporates Kalman-filter-based speed estimation using raw signals directly from

Yang, Hanlong, Li, Miranda

Automatic Generation of HVAC Ducting System Designs Using Topology and Shape Optimization

2025-01-8656

04/01/2025

In this paper, the topology and shape optimization of a vehicle Heating, Ventilation, and Air Conditioning (HVAC) system is presented. The CFD and optimization methodologies are implemented within AcuSolve™ software. The topology optimization algorithm computes the geometry, where the design domain is parameterized with a field of porosity design variables which indicates the material, fluid or solid, throughout the domain. The optimization is performed using the continuous adjoint approach by the Galerkin Least Squares solver on which the AcuSolve™ solver is based. The design is further improved by using shape optimization. To optimize the geometrical shape, a combination of smooth perturbations, in terms of so called morph shapes, are used to deform the geometrical shape in the optimization algorithm. To this end, a parameterization of the design space is done using a moderate number of design variables, each associated with a morph shape. The two optimization phases are connected by

Papadimitriou, Dimitrios, Sandboge, Robert

Modeling and Control Strategies of the Thermal Management System for Electric Vehicles

2025-01-8190

04/01/2025

The electric vehicle thermal management system is a critical sub-systems of electric vehicles, and has a substantial impact on the driving range. The objective of this paper is to optimize the performance of the heat pump air conditioning system, battery, and motor thermal management system by adopting an integrated design. This approach is expected to effectively improve the COP (Coefficient of Performance) of cabin heating. An integrated thermal management system model of the heat pump air conditioning system, battery, and motor thermal management system is established using AMEsim. Key parameters, such as refrigerant temperature, pressure, and flow rate at the outlet of each component of the system are compared with the measured data to verify the correctness of the model established in this paper. Using the established model, the impact of compressor speed on the heating comfort of the cabin under high-temperature conditions in summer was studied, and a control strategy for rapid

Zhang, Min, Li, Liping, Zhou, Jianhua, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin

A Wide Belt Correction Strategy for Belt-Whip and Wheel Ventilation Drag

2025-01-8770

04/01/2025

The increased importance of aerodynamics to help with overall vehicle efficiency necessitates a desire to improve the accuracy of the measuring methods. To help with that goal, this paper will provide a method for correcting belt-whip and wheel ventilation drag on single and 3-belt wind tunnels. This is primarily done through a method of analyzing rolling-road only speed sweeps but also physically implementing a barrier. When understanding the aerodynamic forces applied to a vehicle in a wind tunnel, the goal is to isolate only those forces that it would see in the real-world. This primarily means removing the weight of the vehicle from the vertical force and the rolling resistance of the tires and bearings from the longitudinal force. This is traditionally done by subtracting the no-wind forces from the wind at testing velocity forces. The first issue with the traditional method is that a boundary layer builds up on the belt(s), which can then influence a force onto the vehicle’s

Borton, Zackery

Integrated Body Structure to Accommodate Manual and Power Door Sunshade Variants in a Vehicle

2025-01-8616

04/01/2025

Door sunshade in a vehicle has proven to be very comfortable and luxurious feature to the customers. Luxury vehicles provide power sunshade which is electrically operated with the activation of a switch, whereas cost conscious vehicles provide manual sunshade which requires manual coiling and uncoiling. This study is to develop a door panel structure that can accommodate both the manual sunshade and power sunshade, thereby serving both cost conscious as well as luxury seeking customers. Manual sunshade consists only of cassette, pull bar, spindle mechanism and hooks whereas the power sunshade consists of cassette, pull bar, spindle mechanism, flap mechanism, bowden cable mechanism, actuator and motor. Due to this difference in package, it becomes difficult to accommodate both variants of sunshade into the same body system. However, this study helps in developing a common body structure by ways of effective packaging, modifying the cable and actuator mechanism and critical packaging of

S M, Rahul, d, Anantha, Kakani, Phani Kumar

Finite Element Simulation and Experimental Study of the in-Mold Graining Process

2025-01-8330

04/01/2025

In-Mold Graining (IMG) is an innovative production technology applied to the skin wrapping of automotive interior components. In the design of automotive interior components of door panels and instrument clusters, to overcome process-related problems, such as the thinning of grain patterns and excessive reduction in thickness, simulation of the skin vacuum forming process is required. The Thermoplastic Olefin (TPO) skin material is investigated in this paper, and a viscoelastic mechanical model for this material is established. Dynamic Mechanical Analyzer (DMA) is utilized to perform scan for frequency and temperature, and the tested data is used to obtain key model parameters of the viscoelastic constitutive model. Based on the experimental data, the study explores how to calculate the relaxation time spectrum to describe the viscoelastic properties of TPO material during the vacuum forming process. Numerical simulation of the vacuum forming process of TPO material is conducted using

Chai, Bingji, Guo, Yiming, Xie, Xinxing, Zhang, Qu

Investigation of the Blockage Phenomenon in Closed Wall Wind Tunnels During the Testing of Bluff Automotive Bodies with Large Wakes in Yawed Configurations

2025-01-8786

04/01/2025

The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been very difficult to experimentally analyze the effects that are occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier works by the author and similarly to those studies uses the computational fluid dynamics analysis of three bodies that generate large wakes to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, and forces experienced by the vehicle model when it is in yawed conditions up to 20 degrees. This is accomplished by executing a series of CFD configurations with varying sized cross sections from 0.4% to 14% blockage enabling an approximation of free air conditions as a reference

Gleason, Mark, Riegel, Eugen

Power Loss Estimation in Poly-V Belts for Micro and Mild Hybrid Powertrains Using the Generalized Maxwell Model

2025-01-8316

04/01/2025

In modern automotive powertrains, the front-end accessory drive represents a crucial subsystem that guarantees the proper functioning of micro and mild hybrid configurations and auxiliary vehicle functionalities. The motor/generator (12 V or 48 V), the air conditioning compressor and other accessories rely on this subsystem. Therein, the poly-V belt is the main transmission mechanism. From an efficiency standpoint, its behavior is usually represented through slip and elastic shear phenomena. However, the viscoelastic nature of the compounds that constitute the belt layers demand a more detailed approximation of the loss mechanisms. The quantification of such losses allows evaluating the performance of the e-machine integrated in the powertrain. This work models the belt through a lumped-parameter time-domain model, where domains are discretized into multiple elements and represented through the generalized Maxwell model. Loss contributions due to bending, stretching, compression and

Galluzzi, Renato, Amati, Nicola, Bonfitto, Angelo, Hegde, Shailesh, Zenerino, Enrico, Pennazza, Mario, Staniscia, Emiliano

Development of Ceramic Humidity Regulator (CHR) Using Honeycomb Type PTC Heater to Improve Electric Vehicle Driving Range in Winter

2025-01-8177

04/01/2025

With Rapid growth of Electric Vehicles (EVs) in the market challenges such as driving range, charging infrastructure, and reducing charging time needs to be addressed. Unlike traditional Internal combustion vehicles, EVs have limited heating sources and primarily uses electricity from the running battery, which reduces driving range. Additionally, during winter operation, it is necessary to prevent window fogging to ensure better visibility, which requires introducing cold outside air into the cabin. This significantly increases the energy consumption for heating and the driving range can be reduced to half of the normal range. This study introduces the Ceramic Humidity Regulator (CHR), a compact and energy-efficient device developed to address driving range improvement. The CHR uses a desiccant system to dehumidify the cabin, which can prevent window fogging without introducing cold outside air, thereby reducing heating energy consumption. A desiccant system typically consists of two

Hamada, Takafumi, Shinoda, Narimasa, Konno, Yoshiki, Ihara, Yukio, Ito, Masaki

Modeling Virus Infection Risks in Automobile Cabin

2025-01-8176

04/01/2025

In the post Covid era, risk of infection in conditioned space is getting attention and has generated a lot of interest for the design of the new systems and strategies for the management and operations of the existing HVAC systems. Risk management plays a key role where the amounts of outside air and recirculated airs can be used to mitigate the propagation of the virus within the conditioned space. In other words, ventilation plays a huge role within the conditioned space along with strategies based on UV irradiation, ionization and use of highly efficient filters. Different air purification systems have been created by the researchers based on the titanium oxide-based UV photocatalysis system, filters with MERV ratings higher than 11 (ASHRAE Standard 52.2) and HEPA filters. Recent ASHRAE standard 241 (2023) on infectious diseases recommends using high ventilation rates within the conditioned space to reduce virus concentration, and hence, to reduce the risk of infection. Determining

Mathur, Gursaran

An Experimental Investigation of the Liquid Jet Breakup Characteristics in a Vaporizer under Equivalent Operating Conditions of a Microturbine Combustion Chamber

2025-01-8458

04/01/2025

This study experimentally investigates the liquid jet breakup process in a vaporizer of a microturbine combustion chamber under equivalent operating conditions, including temperature and air mass flow rate. A high-speed camera experimental system, coupled with an image processing code, was developed to analyze the jet breakup length. The fuel jet is centrally positioned in a vaporizer with an inner diameter of 8mm. Airflow enters the vaporizer at controlled pressures, while thermal conditions are maintained between 298 K and 373 K using a PID-controlled heating system. The liquid is supplied through a jet with a 0.4 mm inner diameter, with a range of Reynolds numbers (Reliq = 2300÷3400), and aerodynamic Weber numbers (Weg = 4÷10), corresponding to the membrane and/or fiber breakup modes of the liquid jet. Based on the results of jet breakup length, a new model has been developed to complement flow regimes by low Weber and Reynolds numbers. The analysis of droplet size distribution

Ha, Nguyen, Quan, Nguyen, Manh, Vu, Pham, Phuong Xuan

Demonstration of Model Predictive Control to Optimise Cabin Thermal Comfort in a Battery Electric Vehicle

2025-01-8145

04/01/2025

The focus on thermal system efficiency has increased with the introduction of electric vehicles (EV) where the heating and cooling of the cabin represents a major energy requirement that has a direct impact on vehicle range in hot and cold ambient conditions. This is further exacerbated during heating where EVs do not have an engine to provide a source of heat and instead use stored electrical energy from the battery to heat the vehicle. This paper considers two approaches to reduce the energy required by the climate control and hence increase the range of the vehicle. The first approach considers minimizing the energy to keep the passengers comfortable, whilst the second approach optimizes the heating and ventilation system to minimize the energy required to achieve the target setpoints. Finally, these two approaches are combined to minimize both the passenger’s demand and the energy required to meet the demand. This paper covers the development process from simulation to

Fussey, Peter, Dutta, Nilabza, Milton, Gareth, Ma, He

Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery

2025-01-8154

04/01/2025

A specific thick film heater (TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is estab-lished. The heat transfer and fluid performance of the TFH is analyzed using a computational fluid dynamics soft-ware. The performance of TFH is measured on a test bench, and the measured data is used to validate the developed model. Using the established model, the heating efficiency of TFH is studied for different inlet temperatures and flow rates, and the influence of the fin spoiler structure on TFH heating efficiency and the heating board temperature is investigated. The result indicates that the spoiler structure has a large effect on the board heating temperature, but has little effect on the heating efficiency. An orthogonal experimental design method is used to optimize the design of the fins and water channels, and the purpose is to reduce the board heating temperature for preventing over burning. Under the 25°C inlet

Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin

Development of a New Concept Structure for 4-Way Electric Headrest Adjustment

2025-01-8620

04/01/2025

At present, electric head restraints have been developed locally, so overseas mechanisms are used. In this study, two concept mechanisms were developed, and in addition, one patent for a wing-out head restraint mechanism was additionally applied. The new mechanism has had an excellent effect on cost reduction and improvement of operating noise compared to the current one.

Yu, Sanguk

Effects of Aging on PVC-Based Instrument Panel Skin for Passenger Airbag Deployment Analysis

2025-01-8321

04/01/2025

Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found on how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin

G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar

Analysis of Coolant Flowing and Heat Transfer Performance in High Voltage Heater System

2025-01-8194

04/01/2025

A method for performance calculation and experimental method of a high voltage heater system in electric vehicles is proposed. Firstly, heater outlet temperature and pressure drop of the heater are used as metrics to compare simulation results with experimental data, thereby validating the established model. Then, simulations are performed on two heater flow channel configurations: a cavity flow channel and a cooling fin flow channel. It is observed that the latter significantly reduces the heating plate temperature. This reduction enhances the protection of heating elements and extends their operational lifespan, demonstrating the advantages of incorporating cooling fins into the flow channel structure. The optimization variables for multi-objective optimization include the fin unit length, fin height, fin thickness, fin width, and spacing between two adjacent rows of fins. The optimization objectives include pressure drop, heat transfer efficiency, and heating plate temperature

Gong, Ming, Wang, Xihui, Wang, Dongdong, Shangguan, Wen-Bin

User Experience for Digitalized and Smart Cockpits and Cabins of Next-gen Mobility

EPR2025006

03/31/2025

This SAE Edge Research Report explores advancements in next-generation mobility, focusing on digitalized and smart cockpits and cabins. It offers literature review, examining current customer experiences with traditional vehicles and future mobility expectations. Key topics include integrating smart cockpit and cabin technologies, addressing challenges in customer and user experience (UX) in digital environments, and discussing strategies for transitioning from traditional vehicles to electric ones while educating customers. User Experience for Digitalized and Smart Cockpits and Cabins of Next-gen Mobility covers both on- and off-vehicle experiences, analyzing complexities in developing and deploying digital products and services with effective user interfaces. Emphasis is placed on meeting UX requirements, gaining user acceptance, and avoiding trust issues due to poor UX. Additionally, the report concludes with suggestions for improving UX in digital products and services for future

Abdul Hamid, Umar Zakir

Smart Clusters: Functional Safety Concepts and Requirements

12-08-02-0018

03/28/2025

This study presents a detailed review of a contemporary safety concept for a smart cluster, comprising a multipurpose display and a head unit. It focuses on elucidating the fundamental regulatory requirements for smart clusters within the frameworks of the United States and the European Union, and draws connections to their functional safety requirements and concepts. The article explores a range of safety mechanisms and architectures designed to implement these proposed functional safety requirements. For each mechanism, we provide an in-depth analysis of its benefits and drawbacks, as well as a thorough explanation of its operational logic. This comprehensive evaluation offers valuable insights into developing safer and more efficient smart clusters in line with international regulatory standards.

Anisimov, Valentin, Babaev, Islam, Shinde, Chaitanya

Minimum Standard for Portable Gaseous, Oxygen Equipment

AS1046C (Current)

03/27/2025

This standard is intended to apply to portable compressed gaseous oxygen equipment. When properly configured, this equipment is used either for the administration of supplemental oxygen, first aid oxygen or smoke protection to one or more occupants of either private or commercial transport aircraft. This standard is applicable to the following types of portable oxygen equipment: a Continuous flow 1 Pre-set 2 Adjustable 3 Automatic b Demand flow 1 Straight-demand 2 Diluter-demand 3 Pressure-demand c Combination continuous flow and demand flow.

A-10 Aircraft Oxygen Equipment Committee

COOLING DATA FOR TURBINE ENGINES IN HELICOPTERS

ARP996A (Current)

03/27/2025

A tested method of data presentation and use is described herein. The method shown is a useful guide, to be used with care and to be improved with use.

S-12 Powered Lift Propulsion Committee

Test Procedure for Determining Refrigerant Emissions from Mobile Air Conditioning Systems

J2763_202503 (Current)

03/25/2025

This SAE Standard covers the mini-shed testing methodology to measure the rate of refrigerant loss from an automotive air conditioning (A/C) system. This SAE procedure encompasses both front and rear air conditioning systems utilizing refrigerants operating under sub-critical conditions. The SAE procedure will cover multiple refrigerants to emission testing and is utilized for evaluating air condtioning systems. Heat pump systems can also be evaluated; however, they will have different usage and mission profiles.

Interior Climate Control MAC Supplier Committee

SAE Aerospace Applied Thermodynamics Manual Aerothermodynamic Systems Engineering and Design

AIR1168/3B (Current)03/25/2025

This section presents methods and examples of computing the steady-state heating and cooling loads of aircraft compartments. In a steady-state process the flows of heat throughout the system are stabilized and thus do not change with time. In an aircraft compartment, several elements compose the steady-state air conditioning load. Transfer of heat occurs between these sources and sinks by the combined processes of convection, radiation, and conduction in the following manner: 1 Convection between the boundary layer and the outer airplane skin. 2 Radiation between the external skin and the external environment. 3 Solar radiation through transparent areas directly on flight personnel and equipment and on the cabin interior surfaces. 4 Conduction through the cabin walls and structural members. 5 Convection between the interior cabin surface and the cabin air. 6 Convection between cabin air and flight personnel or equipment. 7 Convection and radiation from internal sources of heat such as

AC-9 Aircraft Environmental Systems Committee

CFD-Based Comfort Parameter Evaluation of a Flow Vectoring Air Vent System for Car Cabins Using a Reduced Order Model

15-18-02-0012

03/03/2025

This computational fluid dynamics (CFD) study examines the comfort parameters of an innovative air vent concept for car cabin interiors using a reduced order model (ROM) and proper orthogonal decomposition (POD). The focus is on the analysis of the influence of geometric and fluid mechanical parameters on the resulting jet, in particular on the deflection angle of the airflow and the total pressure difference along the outlet geometry. Different parameters of the investigated system, such as the surface orientation, the outlet height, the separator distance, and the separator height, lead to different effects on the airflow structure. The results show that changes in the air vent surface orientation are always accompanied by an increase in the deflection angle and the total pressure difference. In contrast, the variation of the outlet height ratio positively influences the deflection angle and the total pressure difference in terms of the requirements for air vent geometries. The study

Langhorst, Sebastian, Mrosek, Markus, Boughanmi, Nesrine, Schmeling, Daniel, Wagner, Claus

R-1234yf Service Hose, Fittings, and Couplers for Mobile Refrigerant Systems Service Equipment

J2888_202502 (Current)

02/25/2025

This SAE Standard covers fittings, couplers, and hoses intended for connecting service hoses from mobile air-conditioning systems to service equipment such as charging, recovery, and recycling equipment (see Figure 1). This specification covers service hose fittings and couplers for MAC service equipment service hoses, per SAE J2843 and SAE J2851, from mobile air-conditioning systems to service equipment such as manifold gauges, vacuum pumps, and air-conditioning charging, recovery, and recycling equipment.

Interior Climate Control Service Committee

Windshield Defrosting Systems Test Procedure and Performance Requirements - Trucks, Buses, and Multipurpose Vehicles

J381_202502 (Current)

02/25/2025

This SAE Recommended Practice establishes uniform test procedures and performance requirements for the defrosting system of enclosed cab trucks, buses, and multipurpose vehicles. It is limited to a test that can be conducted on uniform test equipment in commercially available laboratory facilities. For laboratory evaluation of defroster systems, current engineering practice prescribes that an ice coating of known thickness be applied to the windshield and left- and right-hand side windows to provide more uniform and repeatable test results, even though - under actual conditions - such a coating would necessarily be scraped off before driving. The test condition, therefore, represents a more severe condition than the actual condition, where the defroster system must merely be capable of maintaining a cleared viewing area. Because of the special nature of the operation of most of these vehicles (where vehicles are generally kept in a garage or warmed up before driving), and since

Truck and Bus Windshield Wipers and Climate Control Comm

Study of Different Types of Ventilation and Cooling Systems of Bulb Hydrogenerators in a Three-Dimensional Setting

05-18-03-0020

02/20/2025

The Object of research in the article is the ventilation and cooling system of bulb hydrogenerators. The Subject of study in the article is the design and efficiency of using the cooling system of various structural types for bulb hydro units. The Purpose of the work is to carry out a three-dimensional study of two cooling systems (axial and radial) of the bulb hydro unit of the Kanivskaya HPP with a rated 22 MW. Research Tasks include analysis of the main design solutions for effective cooling of bulb-type hydrogenerators, in particular, the use of radial, axial, and mixed cooling systems; formulation of the main assumptions for the three-dimensional ventilation and thermal calculation of the bulb hydrogenerator; carrying out a three-dimensional calculation for a hydrogenerator with axial ventilation; determining airflow speeds in the channels and temperatures of active parts of the hydrogenerator under the conditions of using discharge fans and without them; carrying out a three

Tretiak, Oleksii, Arefieva, Mariia, Makarov, Pavlo, Serhiienko, Serhii, Zhukov, Anton, Shulga, Iryna, Penkovska, Nataliia, Kravchenko, Stanislav, Kovryga, Anton

Effectiveness of Seat’s Negative Stiffness Structure on Three Different Models of Vehicles

15-18-02-0011

02/08/2025

The effectiveness of the negative suspension structure (NSS) in isolating the driver’s seat vibrations has been demonstrated based on the seat’s model or vehicle’s one-dimensional dynamic model. To fully assess the effectiveness and stability of the seat’s NSS (S-NSS) on different models of vehicles, the three-dimensional models of the vibratory rollers (VR), heavy trucks (HT), and passenger cars (PC) have been built to assess the effectiveness of S-NSS compared to the seat’s passive suspension (S-PC) and seat’s control suspension (S-CS). The effectiveness of S-NSS is then investigated under all operating conditions of vehicles. The investigation results indicate that under a same simulation condition, S-NSS improves the ride comfort and health of the driver better than both S-PS and S-CS on all VR, HT, and PC. However, the effectiveness of S-NSS on PC is lower than on both VR and HT while the effectiveness of S-CS on PC is better than on both VR and HT. Besides, the effectiveness of S

Su, Beibei, Wang, Qiang, Song, Fengxiang

Optimization and Regression Modeling of Additive Manufacturing (Fused Deposition Modeling) of PETG Material for Automobile Applications

2025-28-0146

02/07/2025

In recent years, Additive Manufacturing (AM), more especially Fused Deposition Modeling (FDM), has emerged as a very promising technique for the production of complicated forms while using a variety of materials. Polyethylene Terephthalate Glycol, sometimes known as PETG, is a thermoplastic material that is widely used and is renowned for its remarkable strength, resilience to chemicals, and ease of processing. Through the use of Taguchi Grey Relational Analysis (GRA), the purpose of this investigation is to improve the process parameters of the FDM technology for PETG material. In order to investigate the influence that several FDM process parameters, such as layer thickness, infill density, printing speed, and nozzle temperature, have on significant outcome variables, such as dimensional accuracy, surface quality, and mechanical qualities, an empirical research was conducted. For the purpose of constructing the regression prediction model, the obtained dataset is used to make

Natarajan, Manikandan, Pasupuleti, Thejasree, Shanmugam, Loganayagan, Katta, Lakshmi Narasimhamu, Silambarasan, R, Kiruthika, Jothi

Optimization and Regression Modeling of Fused Deposition Modeling for TPU Material Used in Automotive Instrument Panels

2025-28-0142

02/07/2025

Fused Deposition Modeling (FDM) is a widely recognized additive manufacturing method that is highly regarded for its ability to create complex structures using thermoplastic materials. Thermoplastic Polyurethane (TPU) is a highly versatile material known for its flexibility and durability. TPU has several applications, including automobile instrument panels, caster wheels, power tools, sports goods, medical equipment, drive belts, footwear, inflatable rafts, fire hoses, buffer weight tips, and a wide range of extruded film, sheet, and profile applications.. The primary objective of this study is to enhance the FDM parameters for TPU material and construct regression models that can accurately forecast printing performance. The study involved conducting experimental trials to examine the impact of key FDM parameters, such as layer thickness, infill density, printing speed, and nozzle temperature, on critical responses, including dimensional accuracy, surface quality, and mechanical

Pasupuleti, Thejasree, Natarajan, Manikandan, Sagaya Raj, Gnana, Silambarasan, R, Kiruthika, Jothi

A Simulation Methodology for Rainwater Ingress into Vehicle HVAC Cowl Box with Design Improvement

2025-28-0163

02/07/2025

The main design objectives to be achieved in the design of HVAC cowl box includes minimizing the pressure drop and eliminating the chances of water ingress in HVAC. There are CFD tools available to study the cowl box pressure drop. However, methods available to study rain water ingress in HVAC are expensive in both mesh preparation and computational time. Using SPH (Smooth Particle based Hydrodynamics) based Preonlab tool, an attempt has been made in this work to study the design improvements of HVAC cowl box to eliminate the chances of flooding during raining. ANSYS FLUENT tool used to study the pressure drop of each design. The simulation aims to investigate the pressure drop in the cowl box and the amount of water intrusion into the HVAC module. L9 orthogonal array (factorial study) conducted to study the factors influencing the cowl box pressure drop. Inlet area, drain area and outlet area are the factors considered. Designs with segregated airflow path (adding inner duct) in the

Baskar, Subramaniyan, A, Boopalshanmugam, Raju, Kumar

Thermal Management of Electric Heavy-Duty Truck Equipped with Water Source Heat Pump in Winter Condition

2025-01-7010

01/31/2025

The electric heavy-duty truck has been receiving much attention due to its low carbon emission characteristic. This paper presents the winterized design of thermal management for an electric heavy-duty truck. The changes of important parameters in the modes of rapid heating from a cold start battery, cabin defrosting, and cabin heating in winter are discussed based on water source heat pumps. It takes 1300 seconds to warm the battery to 5°C from an ambient temperature of -10°C. Under the same heat production condition, the proposed water source heat pump can save 28.2% energy comparing with the air source heat pump, the cabin air conditioner air outlet can stay above 40°C for more than 5 minutes, and the cabin temperature can be stabilized at 20°C to meet the heating demand of the crew in winter.

Yu, Bo, Dai, Huwei, Lin, Jiewei, Han, Feng, Jiang, Feifan, Zhang, Junhong

Research on Thermal Management System of New Energy Vehicles Based on Heat Pump Air Conditioner

2025-01-7005

01/31/2025

With the popularity of electric vehicles, the application development of heat pump type automobile air conditioning system has been focused. Meanwhile, the traditional R134a needs to be replaced by more environmentally-friendly refrigerants under the Kigali Amendment. In this paper, a novel direct expansion heat pump air conditioning system with three circuit switching (DXACS) was proposed, and three low GWP refrigerants R1234yf, R1234ze(E) and R290 were carried out to evaluate the system performance. The results show that the winter range attenuation ratio of DXACS is 26.9%, significantly lower than the prototype EV360 (57.5%); the DXACS with R290 shows the best heating performance, COPh and qcv are 2.3% and 57.3% higher than R134a in extremely cold conditions, respectively. This study provides valuable insights for the development of efficient and green thermal management technology of new energy vehicles.

Zhu, Tengfei, Liu, Ye, Chen, Qinghua

Analysis of the Battery Direct Cooling Thermal Management System Coupled with Passenger Cabin Air Conditioning in Extended-Range Vehicles

2025-01-7065

01/31/2025

To investigate the characteristics of a battery direct-cooling thermal management system integrated with the passenger compartment air-conditioning in a range-extended hybrid electric vehicle (REV), a model of the vehicle’s direct-cooling and liquid-cooling thermal management systems was established in GT-SUITE software. The findings are as follows: (1) Under high-temperature fast-charging conditions, the direct-cooling thermal management system exhibited improved performance indicators compared to the liquid-cooling system. Specifically, the charging time was reduced by 3.8%, the maximum heat exchange power increased by 27.33%, the battery temperature decreased by 2.37°C, the thermal decay rate was only 6%, and the average system energy efficiency ratio increased by 8.37%. (2)The outlet pressure of the direct-cooling plate significantly affected the temperature reduction of the battery pack during high-temperature fast-charging. The results indicated that within a certain range, a

Li, Li-Jie, Su, Chuqi, Wang, Yi-Ping, Yuan, Xiao-Hong, Liu, Xun

Fusion Control Strategy Based on Rule and Dynamic Objective of Heat Pump Type Thermal Management System for Electric Vehicles

2025-01-7023

01/31/2025

Thermal management system of electric vehicles (EVs) is critical for the vehicle's safety and stability. While maintaining the components within their optimal temperature ranges, it is also essential to reduce the energy consumption of thermal management system. Firstly, a kind of architecture for the integrated thermal management system (ITMS) is proposed, which can operate in multiple modes to meet various demands. Two typical operating modes for vehicle cooling in summer and heating in winter, which utilizes the residual heat from the electric drive system, are respectively introduced. The ITMS based on heat pump enables efficient heat transfer between different components. Subsequently, an ITMS model is developed, including subsystems such as the battery system, powertrain system, heat pump system and cabin system. The description of modeling process for each subsystem is provided in detail. The model is tested under world light vehicle test cycle (WLTC) condition of six different

Zhao, Luhao, Tan, Piqiang, Yang, Xiaomei, Yao, Chaojie, Liu, Xiang

Steady-State and Dynamic Characteristics of Secondary Loop CO ₂ Thermal System for Electric Vehicles

2025-01-7006

01/31/2025

With the rapid adoption of new energy vehicles (NEVs), effective thermal management has become a crucial factor for enhancing performance, safety, and efficiency. This study investigates the steady-state and dynamic characteristics of a secondary loop CO₂ (R744) thermal management system designed for electric vehicles. The secondary loop system presents several benefits, such as improved safety through reduced refrigerant leakage and enhanced integration capabilities with existing vehicle subsystems. However, these advantages often come at the cost of decreased thermodynamic efficiency compared to direct systems. Experimental evaluations were conducted to understand the effects of varying coolant flow rates, discharge pressure, and dynamic startup behaviors. Results indicate that while the indirect system generally shows a lower coefficient of performance (COP) than direct systems, optimization of key parameters like coolant flow rate and discharge pressure can significantly enhance

Zong, Shuo, He, Yifan, Guan, Yan, Dong, Qiqi, Yin, Xiang, Cao, Feng

Utilizing High-Performance Thermoplastics to Improve Durability and Efficiency in Automotive Instrument Panels

2024-01-5245

01/28/2025

The present research explores the potential of high-performance thermoplastics, Polymethyl Methacrylate and Polyurethane, to enhance the passive safety of automotive instrument panels. The purpose is to evaluate and compare the passive safety of these two materials through the conduct of the Charpy Impact Test, Tensile Strength Test, and Crush Test —. For this, five samples were prepared in the case of each material via injection moulding, which enabled reliability, and consistency of the findings. As a result, it was found that in the case of the Charpy Impact Test, the average impact resistance varies with PMMA exhibiting a level of 15.08 kJ/m2 as opposed to the value of 12.16 kJ/m2 for PU. The Tensile Strength Test produced the average tensile strength of 50.16 for PMMA and 48.2 for PU, which implied superior structural integrity under tension for the first type of thermoplastic. Finally, the Crush Test showed that PMMA is more resistant to crushes on average than PU with the

Natrayan, L., Kaliappan, Seeniappan, Mothilal, T., Balaji, N., Maranan, Ramya, Ravi, D.

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