Numerical simulation on the influence of solar incidence angle on the car internal flow field
This paper simulates and analyzes non-uniform thermal environment in the cabin by means of CFD. The RNG k -ε turbulent model is chosen, and the Discrete Ordinates radiation model is used to calculate the thermal radiation of the cabin. This paper analyses the influence of three different solar incidence angles on the thermal comfort of car occupants. A reference for the optimal research of the evaluation of indoor comfortable environment is given.
Evaluation of Advanced Automotive Seats to Improve Thermal Comfort and Fuel Economy
Automotive ancillary loads have a significant impact on the fuel economy of both conventional and advanced vehicles. Improving the delivery methods for conditioned air is an effective way to increase thermal comfort at little energy cost, resulting in reduced airconditioning needs and fuel use. Automotive seats are well suited for effective delivery of conditioned air due to their large contact area with and close proximity to the occupants. Normally a seat acts as a thermal insulator, increasing skin temperatures and reducing evaporative cooling of sweat. Ventilating a seat has low energy costs and eliminates this insulating effect while increasing evaporative cooling. The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) has applied a combination of experimental testing and modeling to quantify improved thermal comfort and potential fuel savings by using a ventilated seat. The thermal comfort improvement can be used to reduce the A/C heat capacity by 4%, resulting in a predicted A/C fuel use reduction of 2.8% on an EPA highway cycle and 4.5% on an EPA city cycle. This is a 0.3%-0.5% reduction in total vehicle fuel use when the A/C system is on; while modest for an individual car, the potential fuel savings is significant on a national level.
EVALUATING THERMAL ENVIRONMENTS BY USING A THERMAL MANiKiN WiTH CONTROLLED SKiN SURFACE TEMPERATURE
This paper describes a method for measuring nonuniform thermal environments using a new thermal manikin with controlled skin surface temperature. The manikin and its control logic are described, and an equivalent temperature based on the thermal manikin (teq) is proposed and discussed. A method to calculate the PMV index from manikin heat loss is also given. To calibrate these methods, fundamental data were collected. The manikin-based equivalent temperature (teq) is shown to be effective at accounting for the effects of local heat sources and asymmetrical environmental conditions.