The simulation of vehicle engine cooling in a climatic chamber
- Authors: Badenhorst, Kenneth Merwin
- Date: 2011
- Subjects: Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9615 , http://hdl.handle.net/10948/1454 , Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Description: The simulation of vehicle engine cooling validation in a Climatic chamber will benefit all vehicle manufacturers that are responsible for the design or the localization of parts used in a vehicle's engine cooling system. The ability to test the vehicle in-house allows testing at any time of the year; it provides repeatable and comparative data, and accelerates component level approval, which in itself reduces program timing and cost. For this dissertation road level testing was conducted in Upington using a TD1200 Superflow towing dynamometer, while the in-house testing was performed on a ROTOTEST chassis dynamometer in a Climatic chamber. All tests were conducted according to GENERAL MOTORS SOUTH AFRICA global testing standards. Statistical analyses of the test data were used to determine the relationship between parameters measured and results obtained. The major contributors to the simulation process was identified and implemented to improve measurement quality and test results. The result was an accurate simulation between road and chamber testing, hence the possibility of moving away from road testing and conduct simulated chamber testing. The presented dissertation is useful for the understanding of basic vehicle cooling testing and the methodology of simulated testing in an environmentally controlled chamber.
- Full Text:
- Date Issued: 2011
- Authors: Badenhorst, Kenneth Merwin
- Date: 2011
- Subjects: Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9615 , http://hdl.handle.net/10948/1454 , Automobiles -- Motors -- Cooling systems , Automobiles -- Air conditioning
- Description: The simulation of vehicle engine cooling validation in a Climatic chamber will benefit all vehicle manufacturers that are responsible for the design or the localization of parts used in a vehicle's engine cooling system. The ability to test the vehicle in-house allows testing at any time of the year; it provides repeatable and comparative data, and accelerates component level approval, which in itself reduces program timing and cost. For this dissertation road level testing was conducted in Upington using a TD1200 Superflow towing dynamometer, while the in-house testing was performed on a ROTOTEST chassis dynamometer in a Climatic chamber. All tests were conducted according to GENERAL MOTORS SOUTH AFRICA global testing standards. Statistical analyses of the test data were used to determine the relationship between parameters measured and results obtained. The major contributors to the simulation process was identified and implemented to improve measurement quality and test results. The result was an accurate simulation between road and chamber testing, hence the possibility of moving away from road testing and conduct simulated chamber testing. The presented dissertation is useful for the understanding of basic vehicle cooling testing and the methodology of simulated testing in an environmentally controlled chamber.
- Full Text:
- Date Issued: 2011
Modelling and intelligent control of vehicle climatronic systems
- Sun, Jie
- Authors: Sun, Jie
- Date: 2009
- Subjects: Automobiles -- Air conditioning , Automobiles -- Motors -- Cooling systems , Automobiles -- Heating and ventilation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9600 , http://hdl.handle.net/10948/1118 , Automobiles -- Air conditioning , Automobiles -- Motors -- Cooling systems , Automobiles -- Heating and ventilation
- Description: The modelling and control method of a vehicle climatronic system, based on MATLAB/SIMULINK, is presented. In order to achieve high modelling accuracy, a developed simulation model library is introduced. The modelling approach is described and the developed models are validated with some of experimental data obtained. The models are nonlinear, independent of fluid type and based on thermo-dynamic principles. Analysis of the cooling circuit modelling and empirical real-time control models are created by using Fuzzy logic controller and Stateflow. Both of control input and output are implemented essentially at original vehicle CAN-Bus system. Feasible digital automatic control strategy basic to fuzzy theory, hardware and software solution are given. The simulation experiment is achieved with the Hardware-in-Loop technology. This control methodology is easily operated and worth applying for any further studies or methods.
- Full Text:
- Date Issued: 2009
- Authors: Sun, Jie
- Date: 2009
- Subjects: Automobiles -- Air conditioning , Automobiles -- Motors -- Cooling systems , Automobiles -- Heating and ventilation
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9600 , http://hdl.handle.net/10948/1118 , Automobiles -- Air conditioning , Automobiles -- Motors -- Cooling systems , Automobiles -- Heating and ventilation
- Description: The modelling and control method of a vehicle climatronic system, based on MATLAB/SIMULINK, is presented. In order to achieve high modelling accuracy, a developed simulation model library is introduced. The modelling approach is described and the developed models are validated with some of experimental data obtained. The models are nonlinear, independent of fluid type and based on thermo-dynamic principles. Analysis of the cooling circuit modelling and empirical real-time control models are created by using Fuzzy logic controller and Stateflow. Both of control input and output are implemented essentially at original vehicle CAN-Bus system. Feasible digital automatic control strategy basic to fuzzy theory, hardware and software solution are given. The simulation experiment is achieved with the Hardware-in-Loop technology. This control methodology is easily operated and worth applying for any further studies or methods.
- Full Text:
- Date Issued: 2009
Precooling strategies for passenger vehicles
- Wachsmuth, Carsten Ulrich Harro
- Authors: Wachsmuth, Carsten Ulrich Harro
- Date: 2009
- Subjects: Automobiles -- Air conditioning , Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9643 , http://hdl.handle.net/10948/930 , Automobiles -- Air conditioning , Air conditioning
- Description: By ventilating the vehicle’s interior during a soak, the peak cooling load is reduced and therefore the air-conditioning needs less power. This in turn translates to a smaller air-conditioning unit which would consume less power, be lighter and more compact. This solar driven ventilation of the vehicle’s interior during a soak is defined as precooling. During this project the best precooling strategy for passenger vehicles was found by investigating and testing different precooling strategies and evaluating them according to their thermodynamic performance, their potential implementation and their influence on the required cooling performance of the airconditioning cycle. The best performances were achieved by strategies with a high air flow rate and a relatively low air inlet temperature. Two categories of precooling strategies were examined: natural convection and forced convection strategies. Openings in the vehicle’s body that fit to all strategies had to be found; with a big potential concerning their thermodynamic performance and other aspects like prevention against water penetration. The best investigated precooling strategies proved to be the one which used the design outlet as an inlet and the opening of the HVAC as an outlet. With these openings a good air flow through the whole cabin can be guaranteed. In addition to that the strategy only uses existing openings of the body which prevent against water penetration. The required installation space for this strategy already exists and can be considered for the package of next generation vehicles.
- Full Text:
- Date Issued: 2009
- Authors: Wachsmuth, Carsten Ulrich Harro
- Date: 2009
- Subjects: Automobiles -- Air conditioning , Air conditioning
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9643 , http://hdl.handle.net/10948/930 , Automobiles -- Air conditioning , Air conditioning
- Description: By ventilating the vehicle’s interior during a soak, the peak cooling load is reduced and therefore the air-conditioning needs less power. This in turn translates to a smaller air-conditioning unit which would consume less power, be lighter and more compact. This solar driven ventilation of the vehicle’s interior during a soak is defined as precooling. During this project the best precooling strategy for passenger vehicles was found by investigating and testing different precooling strategies and evaluating them according to their thermodynamic performance, their potential implementation and their influence on the required cooling performance of the airconditioning cycle. The best performances were achieved by strategies with a high air flow rate and a relatively low air inlet temperature. Two categories of precooling strategies were examined: natural convection and forced convection strategies. Openings in the vehicle’s body that fit to all strategies had to be found; with a big potential concerning their thermodynamic performance and other aspects like prevention against water penetration. The best investigated precooling strategies proved to be the one which used the design outlet as an inlet and the opening of the HVAC as an outlet. With these openings a good air flow through the whole cabin can be guaranteed. In addition to that the strategy only uses existing openings of the body which prevent against water penetration. The required installation space for this strategy already exists and can be considered for the package of next generation vehicles.
- Full Text:
- Date Issued: 2009
A COP optimized control system for a CO₂ based automotive A/C-system
- Authors: Rapp, Tobias
- Date: 2007
- Subjects: Automobiles -- Air conditioning , Motor vehicles -- Automatic control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9624 , http://hdl.handle.net/10948/773 , Automobiles -- Air conditioning , Motor vehicles -- Automatic control
- Description: In the last few years carbon dioxide received increasing attention as a possible replacement for fluorocarbon-based refrigerants used within present automotive A/C system technology. R-134a is harmless to the ozone layer but the greenhouse effect is more than 1300 times higher than that of an equivalent amount of CO2. Alternative refrigerants are natural gasses such as propane and butane, however these gasses are considered explosive. With many objections raised it appears if CO2 will be the future refrigrant for automotive use. One concern with R-744 is its high operating pressure and suction/discharge pressure difference when compared to common refrigeration processes. A major problem with the CO2 cycle is the loss of effciency at high ambient temperatures. With a COP optimized control system for the expansion value based on pressure, temperature and mass flow of the refrigerant, an effective A/C system for CO2 could be deleloped. This resrach offers basic knowledge of refrigerant cycles and gives an overall view of the refrigerant change-over problem. With the results obtained from the experimental work a better understanding of the CO2 cycle and a better understanding towards effective A/C systems have been realized.
- Full Text:
- Date Issued: 2007
- Authors: Rapp, Tobias
- Date: 2007
- Subjects: Automobiles -- Air conditioning , Motor vehicles -- Automatic control
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9624 , http://hdl.handle.net/10948/773 , Automobiles -- Air conditioning , Motor vehicles -- Automatic control
- Description: In the last few years carbon dioxide received increasing attention as a possible replacement for fluorocarbon-based refrigerants used within present automotive A/C system technology. R-134a is harmless to the ozone layer but the greenhouse effect is more than 1300 times higher than that of an equivalent amount of CO2. Alternative refrigerants are natural gasses such as propane and butane, however these gasses are considered explosive. With many objections raised it appears if CO2 will be the future refrigrant for automotive use. One concern with R-744 is its high operating pressure and suction/discharge pressure difference when compared to common refrigeration processes. A major problem with the CO2 cycle is the loss of effciency at high ambient temperatures. With a COP optimized control system for the expansion value based on pressure, temperature and mass flow of the refrigerant, an effective A/C system for CO2 could be deleloped. This resrach offers basic knowledge of refrigerant cycles and gives an overall view of the refrigerant change-over problem. With the results obtained from the experimental work a better understanding of the CO2 cycle and a better understanding towards effective A/C systems have been realized.
- Full Text:
- Date Issued: 2007
Analysis of fuel consumption reduction potential through the use of an electrically driven air conditioning compressor
- Authors: Marais, Charel
- Date: 2007
- Subjects: Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9623 , http://hdl.handle.net/10948/774 , Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Description: The disturbing current situation regarding the world climate has initiated a major wave of urgent developments towards decreasing the overall impact of human activities on the living environment. A major role player in this development is the automobile industry that is inherently connected to pollution of various types, be it air, water or noise pollution. There have been drastic changes not only in the technologies employed in producing vehicles and components, but also in the construction and technologies built into modern automobiles to lessen the overall environmental impact of the industry. Noxious emissions have been decreased, overall efficiencies increased and vehicles are becoming more economical with each new generation. Stricter laws dictate that the level of acceptable vehicle emissions is to be decreased ever further and all manufacturers are developing various possibilities to achieve this. With the emergence of hybrid vehicle technology, there was also a sudden development of different electrical systems that were made viable by the higher onboard voltage systems employed in hybrid vehicles. One of these developments was the electrical air conditioning compressor for use in automobile applications. Although it is designed to operate with a higher voltage than the traditional 12V onboard vehicle systems, it is theoretically possible to incorporate it into a 12V system by making use of a DC-DC converter to step up the supply voltage of the electrical compressor sufficiently to allow for its successful operation. The question therefore arises whether it would be feasible and sensible to employ an electrical air conditioning system in conventional combustion engine vehicles from an overall fuel consumption and vehicle emissions point of view. A modelling approach was taken where an overall vehicle driving simulation was created to represent an average modern production vehicle. The simulation was then extended to include the options of incorporating models for both mechanically and electrically driven air conditioning systems. This provides insight into the influences of the air conditioning system on the vehicle’s overall fuel consumption and an opportunity to compare the influences from the two different systems. This study attempted to provide answers to some of the viability questions regarding the incorporation of electrically driven air conditioning systems into vehicles that use standard 12V onboard voltage systems. It was found that the electrical system has definite potential as a viable replacement option for the conventional system should it be combined with an appropriate alternator and equipped with an efficient control system.
- Full Text:
- Date Issued: 2007
- Authors: Marais, Charel
- Date: 2007
- Subjects: Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9623 , http://hdl.handle.net/10948/774 , Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Description: The disturbing current situation regarding the world climate has initiated a major wave of urgent developments towards decreasing the overall impact of human activities on the living environment. A major role player in this development is the automobile industry that is inherently connected to pollution of various types, be it air, water or noise pollution. There have been drastic changes not only in the technologies employed in producing vehicles and components, but also in the construction and technologies built into modern automobiles to lessen the overall environmental impact of the industry. Noxious emissions have been decreased, overall efficiencies increased and vehicles are becoming more economical with each new generation. Stricter laws dictate that the level of acceptable vehicle emissions is to be decreased ever further and all manufacturers are developing various possibilities to achieve this. With the emergence of hybrid vehicle technology, there was also a sudden development of different electrical systems that were made viable by the higher onboard voltage systems employed in hybrid vehicles. One of these developments was the electrical air conditioning compressor for use in automobile applications. Although it is designed to operate with a higher voltage than the traditional 12V onboard vehicle systems, it is theoretically possible to incorporate it into a 12V system by making use of a DC-DC converter to step up the supply voltage of the electrical compressor sufficiently to allow for its successful operation. The question therefore arises whether it would be feasible and sensible to employ an electrical air conditioning system in conventional combustion engine vehicles from an overall fuel consumption and vehicle emissions point of view. A modelling approach was taken where an overall vehicle driving simulation was created to represent an average modern production vehicle. The simulation was then extended to include the options of incorporating models for both mechanically and electrically driven air conditioning systems. This provides insight into the influences of the air conditioning system on the vehicle’s overall fuel consumption and an opportunity to compare the influences from the two different systems. This study attempted to provide answers to some of the viability questions regarding the incorporation of electrically driven air conditioning systems into vehicles that use standard 12V onboard voltage systems. It was found that the electrical system has definite potential as a viable replacement option for the conventional system should it be combined with an appropriate alternator and equipped with an efficient control system.
- Full Text:
- Date Issued: 2007
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