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This paper reports a study on Charge air cooler effectiveness, Air intake pressure drop, Acceleration Performance and Rise over ambient temperature of a utility vehicle for different layouts of Inter cooler, radiator, condenser and fan module in order to finalize an efficient Power train cooling system layout. The main objective is effective utilization of front end opening area, eliminating inter cooler heat load on the radiator, so that radiator size, fan size and fan motor wattage can be optimized to achieve desired cooling performance requirements with the cooling system (CRFM) module. Effect of the intercooler effectiveness, Intake pressure drop, Vehicle acceleration performance and Rise over ambient temperature are studied and both the advantages and disadvantages of the proposals are discussed to finalize the better position of inter-cooler along with other engine cooling components.

The paper presents the development of a proposed rear powertrain cooling system of a minivan. The packaging of cooling system is finalized such that the radiator faces towards the rear of the vehicle bumper which is opposite to the conventional rear cooling system (i.e. radiator faces towards the front of the vehicle). In the small minivan, the space ahead of the engine is used as a floor for passenger foot. Due to these space constraints, the cooling system has no choice, but to move rear of the vehicle and above the departure plane to meet packaging requirements. Furthermore, in the conventional rear cooling system, in front of the radiator, there is engine and exhaust system, which heats up the air going to the radiator and reduces radiator cooling performance. Thus the cooling system is placed such that the radiator faces the rear bumper to draw in cooler air.

One of the most essential components of automotive HVAC system is compressor. In a vehicle it is directly mounted on the engine. It derives power from the engine feed system to keep refrigerant moving in the HVAC system of the vehicle. It is also essential to complete the vapor compression cycle. During the operation, it causes considerable load on the engine and thus results in lower fuel efficiency and higher pollution. There are several types of compressors available globally. According to construction it can be classified as reciprocating piston type, scroll type and rotary vane type. The reciprocating piston types of compressors are further classified as fixed displacement and variable displacement. Normally the fixed displacement compressors have good idling cooling performance, but it increases the load on the engine. To reduce the load on the engine and to have good idling cooling performance, generally a variable displacement compressor is used.

One of the most fundamental parameters for designing an automotive HVAC system is the thermal load, also known as cooling load. The major contributors to the thermal load inside the cabin of an automobile are solar loads, occupant loads, infiltration loads and loads due to various electrical fittings and the engine. Simple but accurate predictions of the thermal load inside the cabin will help engineers in designing and developing an efficient mobile air conditioning system. While commercial software are available for simulating these loads, such tools require tedious and time-consuming modeling of components involving many parameters as well as multiple iterations. A simple method for computation of the vehicle thermal load that requires a minimum of input parameters will be useful in situations where a full-scale analysis is not required. A computer model has been prepared for this purpose at Mahindra & Mahindra.

In any engine cooling system, de-aeration capability of the system plays a very critical role to avoid over heating of an engine. In general, with recovery bottle engine cooling system there is one vent hose from radiator pressure cap to the recovery bottle and coolant in the bottle is exposed to atmospheric pressure. From this vent hose air bubbles will move to recovery bottle from the engine and radiator when pressure in the system exceeds pressure cap setting. With this arrangement, de-aeration from the engine will happen when thermostat opens only and till that time air bubbles will be in the engine only and in this time there will be chance of overheating at some critical conditions because of air pockets in to the engine water jacket and the entrained air in the cooling circuit. Also, secondly 100 % initial filling cannot be achieved.

The main function of an air conditioning system in a vehicle is to provide the thermal comfort to the occupant at minimum possible energy consumption in all environmental conditions. To ensure the best possible thermal comfort, air conditioning system is optimized on various parameters like heat load, air flow distribution, glass area, trim quality, insulations and cabin leak rate. A minimum cabin leakage is regulatory requirements to ensure the air quality of cabin. Anything above the minimum cabin leak rate ultimately turn into reduced thermal comfort and additional energy consumption. The additional energy consumption to maintain the required thermal comfort in the cabin due to cabin leakage affects the fuel efficiency severely. In the present study, the effect of cabin leakage on fuel efficiency and thermal comfort is studied in details by varying the cabin leakage through mechanical means. The experiments are carried out in normal environmental condition and road condition.

The traditional approach of engine thermal behavior of engine during startup has largely been dependent on experimental studies and high fidelity simulations like CFD. However, these techniques require considerable effort, cost and time. The low fidelity simulations validated with experimental results are becoming more popular due to their ease in handling the several parameters such as cost effectiveness and quick predictive results. A four point mass model of engine thermal behavior during cold start has been developed to study the engine warm up temperature behavior. The four point mass model considers the lumped mass of coolant, mass of engine directly associated with the coolant, mass of engine oil and mass of engine directly associated with the engine oil. The advantage of four point model is to predict the coolant temperature as well as lubricant temperature during the transient warm up cycle of the engine.

For the thermal management of an automobile, the induced airflow becomes necessary to enable the sufficient heat transfer with ambient. In this way, the components work within the designed temperature limit. It is the engine-cooling fan that enables the induced airflow. There are two types of engine-cooling fan, one that is driven by engine itself and the other one is electrically driven. Due to ease in handling, reduced power consumption, improved emission condition, electrically operated fan is becoming increasingly popular compared to engine driven fan. The prime mover for electric engine cooling fan is DC motor. Malfunction of DC motor due to overheating will lead to engine over heat, Poor HVAC performance, overheating of other critical components in engine bay. Based upon the real world driving condition, 1D transient thermal model of engine cooling fan motor is developed. This transient model is able to predict the temperature of rotor and casing with and without holes.