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Simulation of Driving Cycles by Means of a Co-Simulation Framework for the Prediction of IC Engine Tailpipe Emissions

Exothermia SA-Vasileios Tziolas, Nikolaos Zingopis
Politecnico di Milano-Gianluca Montenegro, Angelo Onorati, Gianluca D'Errico, Tarcisio Cerri, Andrea Marinoni
  • Technical Paper
  • 2020-37-0011
To be published on 2020-06-23 by SAE International in United States
The current European legislation concerning pollutant emissions from IC engine vehicles is very stringent and demanding. In addition, the CO2 fleet emission must obey to a significant reduction path during the next decade, to cope with the prescribed targets recently agreed. The prediction of pollutant emissions from IC engines has been a challenge since the introduction of the emission regulation legislation. During the last decade, along with the more tightening limits and increased public concern about air quality, the capability of simulating different operating conditions and driving cycles with an acceptable computational effort has become a key feature for modern simulation codes. The role of 1D thermo-fluid dynamic simulation models is extremely important to achieve this task, in order to investigate the performances of the next generation of IC engines working over a wide range of operating conditions, under steady-state and transient conditions. This work is based on the idea of integrating two different 1D simulation tools in a co-simulation environment, realizing a strict numerical coupling between the two codes. The main goal is to…
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A CFD Model of Supercritical Water Injection for ICEs as Energy Recovery System

University of Basilicata-Antonio Cantiani, Annarita Viggiano, Vinicio Magi
  • Technical Paper
  • 2020-37-0001
To be published on 2020-06-23 by SAE International in United States
Supercritical water injection for ICEs may be a valid option to recover engine wall heat transfer and energy from exhaust gases, with benefits in terms of efficiency and performances. Water is recovered from exhaust gases and is brought up to supercritical conditions by employing the waste heat during engine operations. A preliminary study of this energy recovery approach has already been performed in an authors’ previous work, by employing a port fuel injection (PFI) internal combustion engine quasi-dimensional model, which has been validated against experimental data, returning satisfactory results in terms of overall efficiency gain. In this work, in order to obtain a more reliable and accurate evaluation of the achievable energy recovery with supercritical water injection, a multidimensional CFD model of the engine has been set and validated. As regards the engine geometry, a simplified axial symmetric engine has been used, in order to reduce the computational time and storage. The combustion has been modelled with an ECFM model using an 88-species and 349-reactions chemical kinetics mechanism, in order to evaluate the pollutant emissions…
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UDM Tip Temperature Control using Thermosyphon Principle

Mahindra & Mahindra, Ltd.-Samson Solomon, Rajesh Thiyagarajan, Parvej Khan
  • Technical Paper
  • 2020-28-0040
To be published on 2020-04-30 by SAE International in United States
In today’s automobile industry where BS6 is posing a high challenge and with limited timeline. The main target is to provide the cooling system to have less impact on the in terms of cost, weight and meeting challenging engineering requirement. Thus, the frugal engineering comes into the picture. An important technology that has come into highlight in recent years is the application of thermosyphon principle for UDM injector cooling thereby reducing the rotation parts and power consumption such as an electric pump. Thermosyphon is a method of passive heat exchange and is based on natural convection, which circulates a fluid without the necessity of a mechanical or electric pump. The natural convection of the liquid commences when heat transfer to the liquid gives rise to a temperature difference from one side of the loop to the other. The Flow through the UDM is maintained by changing Temperature (hence density) of the fluid at one end using the force airflow. The main objective of the UDM cooling is to keep the UDM tip temperature below 120…
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Design and development of a condenser for an Air-conditioning systems working in very high ambient temperature and dusty external environment.

Subros Ltd-Arunkumar Goel, Tamal roy
Subros Ltd.-Yogendra Singh Kushwah
  • Technical Paper
  • 2020-28-0007
To be published on 2020-04-30 by SAE International in United States
The aim of this paper is to highlight the unique requirement of air conditioning systems for very high ambient temperature and dusty environment. Typical requirement of such applications are needed for off road vehicles, tractors, railway etc. Among them the system requirement for railway have it’s own challenges in terms of performance, reliability and serviceability. In one of such applications existing design of air conditioning system was facing the issue of frequent tripping during the peak summer condition. One of the reason was very high dust environment around its condenser area. The level of dust was so high that mesh filter was deployed at condenser front area to prevent choking of condenser fins heat transfer area. The condenser filter cleaning was needed on daily basis to run the AC properly. To solve this problem a newly designed multiflow wave fin type condenser was deployed in place of regular multiflow louver fin condenser. The newly designed system with wave fin condenser have eliminated the need of filter and problem of AC tripping got resolved. The performance…
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Aero-thermal analysis of ventilated passage in a brake disc

Veermata Jijabai Technological Institute-Akshay Mhaske, Sampattakumar Gunadal
  • Technical Paper
  • 2020-28-0011
To be published on 2020-04-30 by SAE International in United States
In this paper, the numerical investigation of a brake disc is done for studying its aero-thermal behaviour and finding alternatives that perform better. In a disc brake, the heat generated due to friction has to be dissipated by one or the other modes of heat transfer. Out of the three modes of heat transfer, convection is to be maximized as others may cause deterioration of neighbouring parts. The disc is of ventilated type and hence the turbulence and mass flow rate through this ventilated area is to be optimized so as to improve the convective heat transfer coefficient. An in-depth study of various design changes previously done for improving heat transfer coefficient in ventilated disc is done and these changes are incorporated in the existing design. Various design combinations using different design tweaks for improving heat transfer coefficient are made and simulated in component testing like conditions, which are validated against previously done actual experiments. Total of 12 different design iterations were simulated and the one with the highest heat transfer coefficient was analysed in…
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Parametric Analysis of Impact of Geometrical Parameters on Thermal Performance in Compact Heat Exchangers

Subros Ltd-Rachit Nawani, Saurabh Suman, Yogendra Singh Kushwah
  • Technical Paper
  • 2020-28-0025
To be published on 2020-04-30 by SAE International in United States
Compact heat exchangers are extensively used in the automotive sector, especially in engine cooling and passenger cabin cooling. Considering the evolution of compact heat exchangers from the past several years, development on the compactness has grown up rapidly with the market demand. In line with the futuristic view, it has become mandatory to optimize their thermal performance along with compactness, manufacturing feasibility and durability requirement. The present work investigates the impact of various geometrical parameters of tube & fin design on the heat transfer coefficient and pressure drop. The parametric study determines the most optimized core matrix by considering the manufacturing constraints using mathematical & analytical modeling. The system is mathematically modeled and then simulated to estimate the heat transfer rate, weight, free flow area, wetted area, etc. The output parameters are normalized with respect to the existing product performance benchmark and the percentage improvement on various criterion are evaluated. This study can be useful for designers to understand the significance of various parameters of heat exchanger design, which can be utilized to optimize their…
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CFD investigation of exhaust gas bypass on truck trolley heating

John Deere India Private, Ltd.-Nitin Dewangan
John Deere India Pvt Ltd-Megha anawat
  • Technical Paper
  • 2020-28-0006
To be published on 2020-04-30 by SAE International in United States
Most of the automobile and off-road vehicles leave the 100% exhaust gases to atmosphere. The temperature of the exhaust gas ranges from 200-350 deg C and the exit velocity of the gas is about 40-100 m/s based on the outlet pipe design. Dump trucks are used to transport mud, sticky waste garbage and sometime ice from one place to dump yard. The paper will describe the approach of partially use the exhaust gases for truck trolley by heating the trolley surfaces from the walls. CFD software is used to evaluate the exhaust system pressure drop and bypass exhaust flow rate requirements for effective heating on trolley wall. The simulation also helped to design the appropriate baffle position for optimum pressure drop and recirculation. Conjugate heat transfer CFD analysis is carried out to predict the flow behavior.
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Numerical Investigations on Heat Transfer and Flow Characteristics of Climate Control Systems in Electric Vehicles

Pranav Vikas India Pvt Ltd-Vijayaraghavan S, Govindaraj D
Pranav Vikas India Pvt Ltd.-Mahendravarman Radha
  • Technical Paper
  • 2020-28-0010
To be published on 2020-04-30 by SAE International in United States
Earth's surface temperatures would increase from 2.90 C to 3.40 C by the year 2100 due to global warming, leads to conceivable calamitous effects on human livelihoods, livestock, ecosystems and biodiversity. Overall globally several policies were made to reduce the carbon dioxide emission and other greenhouse gases. The transportation sector is one of the prominent sources of carbon dioxide emissions. On account of the significant emissions caused by conventional buses, migrating to electric buses which have zero tailpipe emissions for public transport fleets is essential. Taken into consideration of the energy density of traction batteries, and cost, energy utilized for HVAC applications should be optimized. Heat transfer and flow characteristics in the condenser and the evaporator zone of climate control system for electric buses were numerically studied and compared with experimental results. Grid independence and turbulence studies were carried out to develop the CFD methodology for this analysis. Air velocity and temperature was measured at different locations in the climate control system to calculate the flow and thermal performance. Fluid flow and heat transfer characteristics…
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A detailed study of prominent factors affecting evaporator frosting in a mobile air conditioning (MAC) system

Tata Motors Ltd-Prasanna V Nagarhalli, Shrikant M Awate, Mubeen Syed
Tata Motors, Ltd.-Anurag Maurya
  • Technical Paper
  • 2020-28-0014
To be published on 2020-04-30 by SAE International in United States
In an automotive air conditioning system, evaporator is well designed for effective heat transfer between refrigerant and air flowing over the evaporator. Hence, the better cooling and dehumidifying the incoming air. Sometimes, at the low ambient temperature and higher relative humidity conditions a frost is observed. It is accumulated over the evaporator and often become thicker enough to block the flow of air completely passing through the evaporator resulting in a rise in vehicle cabin temperature. Current work presents the probable causes of frost formation and their effects on the performance of evaporator and hence, the performance of the automotive air conditioning system. There are four major factors, thermistor poor response, undercharged and overcharged system, clogged air-filter, and also the type of compressor causing frost formation over the evaporator are considered for analysis. Current work presents the experimental analysis of the evaporator performance in the low ambient conditions with the above factors in different iterations. With the above analysis new methods and guidelines can be generated in order to avoid frost formation over the evaporator.
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Thermal Analysis of Clutch Assembly Using Co-Simulation Approach

Mahindra & Mahindra Ltd-Tanmay Sushant Santra, Nagarajan Gopinathan, Kumar Raju, Ganesh Sugumar, Udaya Paradarami, Vikraman Vellandi
  • Technical Paper
  • 2020-28-0024
To be published on 2020-04-30 by SAE International in United States
Automotive clutches are rotary components which transmits the torque from the engine to the transmission. The flywheel lining rotates with the engine, and the pressure plate is rotating with the transmission input shaft, both parts are rotating at different speeds, dependent on the engine speed and the engaged gear ratio. During the engagement, due the difference in speed of the shafts the friction lining initially slips until it makes a complete engagement. Enormous amount of heat is generated due to the slippage of the friction lining, leading to poor shift quality & clutch failure. Depending on the road & traffic conditions, & frequency of engagement and disengagement of the clutch, it generates transient heating & cooling cycles. The friction coefficient drops sharply until it cannot pass valid torque once temperature exceeds the threshold value. This further worsen clutch slippage and lead to more severe temperature rise. To preform transient CFD simulation, co-simulation methodology is applied, for the clutch to predict operating surface temperature of both pressure, flywheel & air temperature for hill holding with maximum…