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IC engine internal cooling system modelling using 1D-CFD methodology

FCA Engineering India Pvt., Ltd.-Dhananjay Sampat Autade, Amit Kumar, Tharunnarayanan Arthanari, Vaibhav Patil, Kamalakannan J
FCA US LLC-Fu-Long Chang
  • Technical Paper
  • 2020-01-1168
To be published on 2020-04-14 by SAE International in United States
Internal combustion engine gets heated up due to continuous combustion of fuel. To keep engine working efficiently and prevent components damage due to very high temperature, the engine needs to be cooled down. Based on power output requirement and provision for cooling system, every engine has it’s unique cooling system. Liquid based cooling systems are majorly implemented in automobile. It’s important to keep in mind that during design phase that, cooling the engine will lower the power to fuel consumption ratio. Therefore, during lower ambient conditions, the cooling system should be able to uniformly increase the temperature of the engine components, engine oil and transmission oil. This is achieved by circulating the coolant through cooling jacket, engine oil heater and transmission oil heater, which will be heated by the combustion heat. The objective of this study is to build a steady state 1D-model of cooling system; comprising of water pump, cooling jacket, engine head, thermostat, radiator, cabin heater, engine and transmission oil heaters with plumbing system. This 1D model is used to simulate vehicle drive…
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Utilization of bench testing in vehicle thermal system development for extreme cold ambient condition

FCA US LLC-Masuma Khandaker, Ahmed Uddin, Vijay Sanikal, Kaji Fuad, Craig Lindquist, Gary Baker, Sadek Rahman
  • Technical Paper
  • 2020-01-1390
To be published on 2020-04-14 by SAE International in United States
Automotive thermal systems are becoming complicated each year. The powertrain efficiency improvement initiatives are driving transmission and engine oil heaters into coolant network design alternatives. The initiatives of electrified and autonomous vehicles are making coolant networks even more complex. The coolant networks these days have many heat exchangers, electric water pumps and valves, apart from typical radiators, thermostat and heater core. Some of these heat exchangers including cabin heaters deal with very small amount of coolant flow rates at different ambient conditions. This paper describes how viscosity can be a major reason for simulation inaccuracy, and how to deal with it for each component in the coolant network. Both experimental and computational aspects have been considered in this paper with wide range of ambient temperatures. Methods have been proposed to handle these issues in the simulation phase at the early phase of automotive thermal system development, especially during extreme cold ambient conditions.
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Investigate partial cabin air re-circulation strategy to improve HVAC system's heating performance using 1D simulation

FCA Engineering India Pvt., Ltd.-Saurabh Belsare, Prakashbabuji Danapalan, Saravanan Sambandan
FCA US LLC-Murali Govindarajalu
  • Technical Paper
  • 2020-01-0159
To be published on 2020-04-14 by SAE International in United States
In cold weather conditions, cabin heating performance is critical for retaining the thermal comfort. Heat is absorbed from the engine by circulating coolant through the engine water jacket and same will be rejected by the heater core. A variable speed blower is used to transfer heat from the heater core to the passenger compartment through floor ducts. The time taken to achieve comfortable cabin temperature determines the performance and capacity of heating ventilating and air conditioning (HVAC) system. In current automotive field, the engine options are provided to customers to meet their needs on the same vehicle platforms. Hence few engine variants cannot warm the cabin up to customer satisfaction. To improve the existing warm up performance of system, Positive thermal coefficient heater (PTC), electric coolant PTC heater, auxiliary pump etc. can be used which increases the overall cost of the vehicle. During warm-up, HVAC system operates in 100% fresh mode. In this study, Partial cabin re-circulation is investigated to understand the effect on the cabin warm-up. In order to demonstrate this phenomenon, a one…
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Development of Cooling Fan Model and Heat Exchange Model of Condenser to Predict the Cooling and the Heat Resistance Performance of Vehicle

Honda R&D Co., Ltd.-Yuichi Fukuchi, Kunihiko Yoshitake, Kazutaka Yokota
  • Technical Paper
  • 2020-01-0157
To be published on 2020-04-14 by SAE International in United States
The cooling performance and the heat resistance performance of commercial vehicle are balanced with aerodynamic performance, output power of power train, styling, the location of sensors, cost and many other parameters. Therefore, it is desired to predict the cooling performance and the heat resistance performance with high accuracy at the early stage of development. Three forms of heat transfer consist of conduction, convection and radiation. Among of these components, it is sometimes difficult to solve the thermal conduction accurately, because to prepare accurate shape and properties needs lots of time and efforts at the early stage of development. Therefore, the cooling performance of heat exchangers and the air temperature distribution in the engine compartment are predicted to access the cooling and the heat resistance performance of vehicle at the preliminary design stage. The air temperature distribution is dominated by the distribution of heat radiation on heat exchangers, the flow distribution which is produced by fans and thermal convection at the surface of parts in the engine compartment. For the case of middle or high vehicle…
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The effect of an active thermal coating on efficiency and emissions from a high speed direct injection diesel engine

Thistle Dubh Ltd.-Robert Gilchrist
University of Oxford-Nick Papaioannou, Felix Leach, Martin Davy
  • Technical Paper
  • 2020-01-0807
To be published on 2020-04-14 by SAE International in United States
This study looked into the application of active thermal coatings on the surfaces of the combustion chamber as a method of improving the thermal efficiency of internal combustion engines. The combination of low thermal conductivity and low heat capacity that these coatings are offering, reduces the temperature gradient between the hot combustion gases and the cooler surroundings during the engine cycle thus leading to lower heat transfer losses and increased piston work. The use of such coatings also results in increased exhaust temperatures which has the potential to improve the cold start performance of after-treatment systems. The active thermal coating was applied to a production aluminium piston and its performance was compared against a reference aluminium piston on a single-cylinder diesel engine. The two pistons were tested over a wide range of speed/load conditions and the effects of EGR and combustion phasing on engine performance and tailpipe emissions were also investigated. A detailed energy balance approach was also employed to study the thermal behaviour of the active thermal coating. In general, improvements in indicated specific…
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“Omega” fin design for enhanced cooling capability on IGBTs

Senior Flexonics-Brian Costello, Ryan Collins
  • Technical Paper
  • 2020-01-0597
To be published on 2020-04-14 by SAE International in United States
Vehicle electrification is a rapidly growing and developing technology. As with any new technology there are hurdles that must be overcome as development marches forward. Overcoming these obstacles will require new and innovative solutions. One area of electrification that is quickly developing is the ability to convert voltage from AC to DC and from DC to AC. This is important since the battery pack outputs a DC voltage which must be converted to AC to drive the electric motor. The reverse is true when braking, the AC voltage generated by the electric motor is converted to DC in order to charge the battery. The conversion of voltage back and forth is controlled through the use of an inverter. The inverter uses Insulated-Gate Bipolar Transistors or IGBTs which generate heat while in operation. As the IGBTs heat up there efficiency goes down. In order to maintain a high level of efficiency the circuity can be directly cooled through the use of a heat sink. A unique “omega” fin design has been developed for use in IGBT…
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Starting process control of a 2-cylinder PFI gasoline engine for range extender

Tongji University-Minglong Li, Ran Zhang, Xingyu Zeng, Weiqi Ding, Weiang Mao, Shaoye Jin, Rufeng Xu, Dengke Yuan, Zongjie Hu, Zaimin Zhong, Liguang Li
  • Technical Paper
  • 2020-01-0315
To be published on 2020-04-14 by SAE International in United States
With the increasing worldwide concern on environmental pollution, blade electrical vehicles (BEV) have attracted a lot attention. However, it still couldn’t satisfy the market requirements because of the low battery power density, high cost and long charging time. The range-extended electrical vehicle (REEV) got more attention because it could avoid the mileage anxiety of the BEVs with lower cost and potentially higher efficiency. When internal combustion engine (ICE) works as the power source of range extender (RE) for REEV, its NVH, emissions in starting process need to be optimized. In this paper, a 2-cylinder PFI gasoline engine and a permanent magnet synchronous motor (PMSM) are coaxially connected. Meanwhile, batteries and load systems were equipped. The RE co-control system was developed based on Compact RIO, Labview and motor control unit (MCU). Focused on the starting process, the effects of first firing speeds, throttle control strategies and coolant temperatures were tested. The results show that the higher first firing speed is preferred without obvious torque fluctuation, and longer throttle switching duration to high load results in lower…
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A new approach for designing and testing engine coolant pump electrically actuated

University of L'Aquila-Marco Di Bartolomeo, Fabio Fatigati, Davide Di Battista, Roberto Cipollone
  • Technical Paper
  • 2020-01-1161
To be published on 2020-04-14 by SAE International in United States
Fuel consumption reduction and CO2 emissions saving are the present drivers of the technological innovation in Internal Combustion Engines for the transportation sector. Among the numerous technologies which ensure such benefits, the role of the cooling pump has been recognized, mainly referred to the possibility to improve engine performances during warm up. During engine homologation, an additional benefit on the fuel consumption can be also reached reducing the energy demand of the pump. In fact, during the cycle, propulsion power requested by the vehicle is low and the importance of the energy absorbed by the pump became significant, since the pump operates far from its maximum efficiency. Indeed, the pump is usually designed at high load working point (Best Efficiency Point, BEP), where the cooling request is maximum: starting from these design conditions, when the pump operates at lower engine coolant requests (as it happens very frequently and more specifically during the homologation cycle of the engine), its efficiency can be very low. This aspect invites pump designer to take care about the choosing of…
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Thermal performance augmentation of automobile radiator using water-based Al2O3 and CuO nanofluid as a coolant

S V National Inst. of TechnologySurat-Akashkumar Pravinbhai Parmar
S.V. National Inst. of Technology, Surat-Mahendrakumar Maisuria, Manishkumar K. Rathod
  • Technical Paper
  • 2020-01-1340
To be published on 2020-04-14 by SAE International in United States
In the recent past, rapid development in the performance of vehicle engine has taken place. Attempts are going on to produce high-efficiency engines at a minimum possible cost in order to fulfill the requirements of customers. However, usage of low thermal conductivity engine coolant limits the ability of cooling system to extract the heat, which ultimately results into difficulties in maintaining the compact size of cooling system. Also, increasing the cooling rate by conventional technologies i.e. providing fins and microchannel has already reached their limits. One of the alternative efforts to improve cooling rate in an automotive radiator to immerge and analyze new types of cooling fluids. Thus, in the present work, the experimental and analytical analysis is carried out to investigate the thermal performance of corrugated finned flat tube car radiator using water-based Al2O3 and CuO Nano fluid. Augmentation of heat transfer process is studied for Nano fluid in comparison to water coolant. The Nano fluid is prepared considering 0.2% Vol. concentration of Nanoparticle with water as a base fluid. A numerical code is…
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Powertrain Thermal System Development for small BEV

Honda R&D Co., Ltd.-Yoshikazu Ohnuma, Yosuke Yamagishi, Katsuya Minami
  • Technical Paper
  • 2020-01-1383
To be published on 2020-04-14 by SAE International in United States
The dynamic performance of battery electric vehicles (BEV) is affected by battery output power, which depends on state of charge (SOC) and the temperature of battery cells. The temperature of the batteries varies in particular with the environment, in which the user stores the vehicle, and the battery output power. It is therefore necessary to employ thermal management systems that can control the battery temperature within the optimal range under severely hot and cold conditions in BEVs. A highly sophisticated thermal management system and its operation strategy were developed to fulfill the above requirements. The powertrain components to be thermo-controlled were located into two coolant circuits having different temperature range. The compact and efficient front-end heat exchangers were designed to optimally balance the cooling performance of powertrain, cabin comfort, vehicle aerodynamics and the vehicle design. The battery pack was optimally thermo-controlled by precisely controlling two 3-way valves in all driving and environmental conditions. To reduce the temperature variation between battery cells, the coolant passage including cooling plates in the battery pack were designed so that…