"Introduction Automotive emission reduction and fuel economy are high on the agenda of government regulatory bodies in an ongoing effort to improve engine performance and reduce environmental pollution. One of the key ways to accomplish these goals is through a well-developed thermal management system. With about 30% of the fuel intake energy dissipated through the cooling system and another 30% through the exhaust system@ it is to be expected that a major energy saving can be achieved with a well-designed thermal management system. Introduction of newer components such as the exhaust gas recirculation (EGR) module@ replacement of the thermostat with a less-restrictive@ more responsive device@ and utilizing an alternative coolant are all examples of component or product improvement which add up@ resulting in a higher thermal efficiency. In the paper ""Thermal Management Concepts for Higher-Efficiency Heavy Vehicles@"" Wambsganss [I-1] takes a general look at such improvements and the accompanying respective benefits. Cortona and Onder [I-2]@ Wagner et al. [I-3]@ and Wagner et al. [I-4] in the respective papers ""Engine Thermal Management with Electric Cooling Pump@"" ""Coolant Flow Control Strategies for Automotive Thermal Management Systems@"" and ""Smart Thermostat and Coolant Pump Control for Engine Thermal Management Systems"" provide an in-depth analysis depicting the gains in replacing the conventional mechanically driven pump with an electric pump@ and the traditional thermostat with an electrically actuated valve. Such benefits include the reduction in the volume of coolant required@ and in the engine warm-up time following cold start. Cold start thermal management is itself a focus within engine thermal management. A cold engine has significantly higher fuel consumption than a warm engine. The earlier the engine is warmed up@ the lower the fuel consumption@ hence the operating cost. The paper ""Thermal Management on Small Gasoline Engines"" by Mueller et al. [I-5] investigates the optimum warm-up sequence and heat management on a small gasoline engine@ with a resulting improvement in fuel consumption and reduction in emission. In their paper ""Cold Start Thermal Management with Electrically Heated Catalyst: A Way to Lower Fuel Consumption@"" Presti et al. [I-6] discuss the use of electrically heated catalyst to improve engine cold start. The electrical energy so obtained is generated from the engine mechanical energy. With continuously increasing gadgetry in modern vehicles@ the average temperature in the engine compartment has seen significant increase@ and the trend continues. The heat transfers to passengers through conduction in the vehicle underbody and in the fire wall. It is important to be able to divert the heat away from passengers as well as from some components that may have reduced performance or completely fail at excessive temperatures. Heat shields are used to contain such excessive temperatures@ and appropriately direct the thermal flow. Undercarpet@ exhaust@ and firewall insulation are some of the applications of heat shields as part of automotive thermal management. Although heat shields are generally used to direct heat away from a certain component or region@ they are sometimes used to direct heat to an area so as to improve the performance of the component. Such is the case when trying to achieve a rapid catalytic converter light-off. It is crucial to have the right insulation material@ not only to provide the desired thermal containment but also for endurance. The paper ""Heat Management By Means Of Thermal Barriers Of Ceramic Fibers In Automotive Components And Systems"" by Leone [I-7] discusses the use of ceramic fibers to accomplish the desired insulation. Underhood architecture also has a contributory effect on the thermal performance. Winnard@ Venkateswaran@ and Barry [I-8] present an experiment in which radiator fan air is diverted from the engine compartment to reduce the underhood temperature in the paper ""Underhood Thermal Management by Controlling Air Flow"". It points at the added benefit of blowing forced air over thermally shielded exhaust manifold. Simulations are effective ways of reducing the cost of building an acceptable thermal system. The paper ""CFD Approach on Underhood Thermal Management of Passenger Cars and Trucks"" by Costa [I-9] discusses the use of simulation and the interaction between the computational and the experimental groups as the design is iterated until an optimum design is achieved. As continuous design improvements are made@ one reaches a point at which neither component nor process can be improved further using the knowledge base at the time. At that point@ we say that we have reached the pinnacle of design optimization for the system. In the case of the cooling system design@ the pinnacle of design optimization is reached when the respective modules and the pipes??material and path??have been optimized for a given fluid. But what if the coolant itself can be improved? Breakthroughs in nanotechnology and the onset of picotechnology have enabled the creation of coolants with significantly improved heat transfer properties. Metallic nanoparticles and nanofluids with oxides show higher conductivity than the traditional coolant. In the paper ""Nanofluids for Vehicle Thermal Management@"" Choi et al. [I- 10] discuss nanofication of coolant to improve heat rejection and consequently@ engine performance."
SAE PT-167-2015 history
2015SAE PT-167-2015 Thermal Management in Automotive Applications