SASTech - Technical Journal of RUAS

Automotive thermal comfort is of crucial importance to enhance the competitive ability of an automobile for satisfaction of consumer's requirement. Effect of different vent shapes for same duct geometry is studied for thermal comfort of passenger. Also, effect of vent shapes on velocity at vent outlet, pressure drop across ducts and overall flow distribution from ducts also part of study of this thesis. Changes in vent shape can affect major results in velocities over manikin and hence the temperature distribution inside cabin. Use of CFD tools to simulate car environment and assessment of thermal comfort is needed for improvement in HVAC design and performance analysis.

Vehicle cabin environment is continuously changing phenomenon and there is a need for transient analysis in order to study passenger thermal comfort. In order to save computational effort, convective heat transfer is decoupled from the other two modes and solved in FLUENT. These results are then fed as inputs to RADTHERM to solve conduction and radiation equations. This way, the total compute time required is made manageable in order to study various geometric changes to the vents. Five geometries of vent shapes of same opening area have been analyzed and same louvers directivity and performance was checked for airflow management inside a passenger car cabin.

For the same duct geometry, occupant comfort levels could be improved by changing only vent. Change in vent shapes at outlet of ducts louvers improves flow velocity and directivity, helping the overall flow management inside a car cabin. Velocities and temperatures at chest and face level are of crucial importance for thermal comfort of passengers. Even though design of vent shapes is dictated by aesthetics and style, its importance can be considered at earlier stage of vehicle development for optimizing performance of cabin cooling for thermal comfort of passengers.