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.
Design of a multiple-lamp large-scale solar simulator
A simple solution to the conflicting constraints of providing uniformity and collimation of irradiance in multiple-lamp solar simulators is proposed. As proof of concept, irradiance measurements obtained in a simulator comprised of 28 1-kW mercury-iodide gas discharge lamps and capable of irradiating a 1.22 m-by-2.44 m collector plane are given. The design is based on preventing a portion of the light from each bulb from reaching the collector plane. Light blockage is achieved by placing a ''shadow board'' 1.02 m from and parallel to the plane of the lamps. Lamps are arranged in a hexagonal pattern with 4 columns of 7 lamps at a lamp-to-lamp spacing and column-to-column spacing of 0.45 m. Lamp-to-collector plane distance is 3.05 m. The design is determined from measurements of the spatial distribution of radiant energy from a single lamp. Irradiance from an array of lamps is then simulated. Measurements of irradiance in the full-scale simulator confirm that uniformity and collimation conform to the American Society of Heating, Refrigerating and Air Conditioning Engineers' standard. Average irradiance is 1,080 W/m[sup 2]. Maximum irradiance is 1,190 W/m[sup 2] and minimum irradiance is 980 W/m[sup 2]. Every point on the plane of the collector receives 100 percent ofmore » radiant energy from an area on the lamp array contained within a subtended angle of 20 deg.« less