The SAE MOBILUS platform will continue to be accessible and populated with high quality technical content during the coronavirus (COVID-19) pandemic. x

Your Selections

Valves
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Adaptation of Subcool Condenser for An Air Conditioning System Employing An Internal Heat Exchanger.

Subros Ltd-Saurabh Suman, Yogendra Singh Kushwah, Suraj maske
  • Technical Paper
  • 2020-28-0026
To be published on 2020-04-30 by SAE International in United States
Recently, the use of air conditioning systems is growing rapidly due to increasing global temperatures. Considering enormous growth in the application of the air conditioning system, there is an urgent need to improve design, performance, and efficiency thereof. For example, the air conditioning systems that are being used these days are required to provide improved efficiency per unit of power consumed, and they are also required to have a smaller form factor as compared to conventional air conditioning systems. Therefore, a lot of modern air conditioning systems employ components such as internal heat exchangers, thermal expansion valves and forth to improve their performance while having a small form factor. In this study a condenser is adapted to be used for an air conditioning system employing an internal heat exchanger. Wherein the condenser subcool area is in a optimized range of a frontal condenser area; and a free flow area within the plurality of tubes of the subcool region of the at least one refrigerant flow section for the refrigerant flow within the plurality of tubes…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Refrigerant Valves in AC- and Heat Pump systems for Electric Vehicles

Otto Egelhof GmbH & Co. KG-Eike Willers
Otto Egelhof GmbH&Co. KG-Stephan Wild
  • Technical Paper
  • 2020-28-0038
To be published on 2020-04-30 by SAE International in United States
Abstract The Thermal Management of Electric Vehicles differs strongly from the Thermal Management in IC engine driven vehicles. The Air Conditioning Circuit itself has comparable requirements, however, the electric components and their properties lead to new architectures. Essential is at least a chiller for the conditioning of the battery, which needs to be cooled down to the range of summer ambient temperatures. The respective control devices need to fulfill different basic requirements - Small package - Lightweight - Low noise - Low energy consumption - High control accuracy to play an important role in the Refrigeration architecture of Electric and Hybrid Vehicles. For conventional systems, optimization of package and weight will be achieved by a 75g TXV with a 28 mm thermal head. As soon as a battery also has to be cooled, Shut-Off valves will be implemented in the system in order to manage the respective heat loads according to the needs. For some system configurations, it is important to have a precise electronic control, which is not following the usually fixed superheat characteristic…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Dynamic behavior of in-cylinder pressure causing fatigue failure of reed valves

Subros Ltd.-Ankit Shukla, Paulson Parayil, Arun Kumar Goel, Kamal Sharma
  • Technical Paper
  • 2020-28-0031
To be published on 2020-04-30 by SAE International in United States
For years, researchers have presented numerous studies that consider interaction between working fluid and reed valve motion in displacement compressors. The computing capacities and available CFD and FEA simulation tools have allowed modeling of fully coupled interaction of fluids and moving structures. The present paper describes our experience and results from developing a simplified model of a multi-cylinder reciprocating piston compressor and estimation of pressure surge during sudden acceleration of such compressors. The results show that sudden speed change causes surge in pressures due to formation of pressure waves that reflect back and forth within cylinder. For the chosen geometry and operating conditions, the duration of such waves is much shorter (~ 0.2ms) as compared to longer response time of reed valves (1 ms) that are stiff and highly inelastic. These high pressure waves eventually exceed the fatigue limit of reed valves and cause failures. These pressure waves also influence the performance of reciprocating by causing noise and vibrations which eventually dissipate in to heat thereby lowering the COP of compressor. Simulation results compare well…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental analysis of HVAC system level noise in mobile air conditioning (MAC) system

Tata Motors Ltd-Prasanna V Nagarhalli, Uttam Titave
Tata Motors, Ltd.-Anurag Maurya
  • Technical Paper
  • 2020-28-0035
To be published on 2020-04-30 by SAE International in United States
With the advent of new technologies and rigorous research and development in engines, cars are becoming quieter than ever. This has led to the noises which were earlier, masked behind engine noise being audible inside the passenger compartment. Having a quieter air-conditioning (AC) system would aid us in cutting down on this parasitic noise source. Making it one of the important parameters during the design and development of the Heating, Ventilation and Air-Conditioning (HVAC) system for a vehicle program. However, due to packaging constraints improper integration or selection of different AC parts, there is a possibility that the noise generated from the AC compressor to get amplified while the refrigerant flows through the thermal expansion valve (TXV) or through pipes. This is because the pressure pulsation, in the refrigerant flow, travels along the pipes and can amplify the noise if it is not properly dampen out. Also, TXVs can also be a source for noise if the quality of refrigerant - dryness fraction - is not optimized at the entry. The objective of the current…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Stability of Flowing Combustion in Adaptive Cycle Engines

Illinois Institute of Technology-Prashanth Tamilselvam, Francisco Ruiz
  • Technical Paper
  • 2020-01-0296
To be published on 2020-04-14 by SAE International in United States
In an Adaptive Cycle Engine (ACE), thermodynamics favors combustion starting while the compressed, premixed air and fuel are still flowing into the cylinder through the transfer valve. Since the flow velocity is typically high and is predicted to reach sonic conditions by the time the transfer valve closes, the flame might be subjected to extensive stretch, thus leading to aerodynamic quenching. It is also unclear whether a single spark, or even a succession of sparks, will be sufficient to achieve complete combustion. Given that the first ACE prototype is still being built, this issue is addressed by numerical simulation using the G-equation model, which accounts for the effect of flame stretching, over a 3D domain representing a flat-piston ACE cylinder, both with inward- and outward-opening valves. A k-epsilon turbulence model was used for the highly turbulent flow field. It was found that the flame would suffer local blow-off under most operating conditions, but the blow-off is never complete so that the regions affected are later re-ignited by the remaining parts of the flame, and combustion…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Minimizing Disturbance Detection Time in Hydraulic Systems

General Motors LLC-Paul Otanez, Ramadityanand Bhogadi
  • Technical Paper
  • 2020-01-0263
To be published on 2020-04-14 by SAE International in United States
In a hydraulic system, parameter variation, contamination, and/or operating conditions can lead to instabilities in the pressure response. The resultant erratic pressure profile reduces performance and can lead to hardware damage. Specifically, in a transmission control system, the inability to track pressure commands can result in clutch or variator slip which can cause driveline disturbance and/or hardware damage. A variator is highly sensitive to slip and therefore, it is advantageous to identify such pressure events quickly and take remedial actions. The challenge is to detect the condition in the least amount of time while minimizing false alarms. A Neyman-Pearson and an energy detector (based on auto-correlation) are evaluated for the detection of pressure disturbances. The performance of the detectors is measured in terms of speed of detection and robustness to measurement noise. The implications in terms of computations and memory utilization of implementing the detectors in real-time embedded systems are also discussed. Both simulation and hardware examples are presented. The hardware experiment is performed in a hydraulic system with low damping composed of a solenoid…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Co-simulation Methodology for PHEV Thermal System Development

FCA US LLC-Rezwanur Rahman, Auvi Biswas, Craig Lindquist, Masuma Khandaker, Sadek Rahman
  • Technical Paper
  • 2020-01-1392
To be published on 2020-04-14 by SAE International in United States
Thermal development of automotive applications is a lot more complex than it used to be in the past. Specifically, for Plug-in Hybrid Electric Vehicles (PHEVs), all the sub-systems are so intertwined that it’s hard to analyze them as sub-systems only. A system level solution is needed for proper sizing of components. For early thermal development, a co-simulation method can ensure that we take into account the inter-dependency of all the thermal features in the car. As for example a large PHEV battery may need to be passively cooled by refrigerant, which is in turns associated with the interior HVAC cooling system. For proper sizing of the condenser, chiller etc., one has to account for the battery cooling and cabin cooling as one system. There are also many thermal actuators on a PHEV, e.g. control valves, pulse-width-module (PWM) pumps, electric compressor, electric coolant heaters etc. Smart controls and calibration development early in the product development can impact sizing of front end cooling modules and other heat exchangers significantly. The design of hardware and software has to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Competitive Approach to an Active Exhaust Heat Recovery System Solution

Tenneco Inc.-Adam Kotrba, Timothy Gardner, John Stanavich, Raphael Bellard, Brian Kunkel, Nicholas Morley
  • Technical Paper
  • 2020-01-0161
To be published on 2020-04-14 by SAE International in United States
As greenhouse gas regulations continue to tighten, more opportunities to improve engine efficiency emerge, including exhaust gas heat recovery. Upon cold starts, engine exhaust gases downstream of the catalysts are redirected with a bypass valve into a heat exchanger, transferring its heat to the coolant to accelerate engine warm-up. This has several advantages, including reduced fuel consumption, as the engine’s efficiency improves with temperature. Furthermore, this accelerates readiness to defrost the windshield, improving both safety as well as comfort, with greater benefits in colder climates, particularly when combined with hybridization’s need for engine on-time solely for cabin heating. Such products have been in the market now for several years; however they are bulky, heavy and expensive, yielding opportunities for competitive alternatives. Customer voice expresses needs for less complex designs that reduce package space, mass and part count (i.e. cost) while maintaining or improving performance, including the integration of an active bypass control valve. This paper highlights the design of an exhaust heat recovery system including relative benchmarking of commercially available products, comparing various aspects of…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigation into the deformation of injector components in a common rail system based on numerical simulation

Beijing Institute of Technology-Dan Xu, Baigang Sun, Qing Yang, Dongwei Wu
  • Technical Paper
  • 2020-01-1398
To be published on 2020-04-14 by SAE International in United States
The deformation of fuel injection system components cannot be disregarded as the pressure of the system increases. In particular, the control plunger and the needle of the solenoid injector tend to deform under high working pressure. Their deformation directly affects the volume of the control plunger chamber and the cross-section area of the fuel that enters the sac. A change in chamber volume influences the characteristics of needle movement, whereas a change in cross-section area influences needle movement and injection quantity. Consequently, the deformation of the injector bring difficulties to the precise control of the fuel injection system. In this study, a ADINA (a finite-element software) model of a BOSCH solenoid injector is established to calculate the structural deformation of the nozzle, the needle and the control plunger under different pressures. The accuracy of the model is validated using experimental data published in prior studies. The validated model is used to calculate the structural deformations of the injector components when the solenoid valve is non-energized and energized. Corresponding results indicate that the maximum deformation location…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

High Efficiency Intake System Leveraging Exhaust Thermal Boost

Finitronx-Xianzhe Jia
University of Pennsylvania-Qianyu Ouyang
  • Technical Paper
  • 2020-01-0277
To be published on 2020-04-14 by SAE International in United States
This IC engine amelioration tackles the hurdling barrier of ICE’s intrinsic efficacy limit through innovative mechanical design of a consolidated system encompassing intake bypass and coordinating injection mechanism. To be specific, a CFD-optimized passage is constructed alongside the intake and injection design which utilizes multi-stage variable mixing precisely, taking full advantage of exhaust temperature elevation. Regenerative heat gained through exhaust system gives rise to flexible amount of thermal dynamics adjustment to the intake. Furthermore, variable geometry intake port is developed based on maximizing air-fuel interaction rate under different circumstances, where high temperature turbulence optimization is implemented in ANSYS Fluent. Pin-slider mechanic design at intake interface enables modular variable intake routing supporting engine efficiency promotion. Regarding ECU development, integrated valve, intake airflow, as well as injection control are designed to cooperate with each other under the supervisory control module. First, optimal controlled valve system is devised at the junction of bypass, which achieves improved response accuracy and combustion sufficiency with flow and temperature regulation. Secondly, a closed-loop injection control strategy fulfills variable in-cylinder combustion tuning with…