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The safety and comfort aspects of passenger vehicles are significant sales argument and have become a topic of rising importance during the development process of a new vehicle. The objective of this study is to compare the performance of several current model vehicles, highlight the drawbacks of current defrosting/demisting systems and point the way to improved passive mechanisms. The investigation is experimental. The work presented is an experimental and numeric investigation of the clear-up pattern of a current vehicle fitted with an electrically heated windshield. Nottingham FDL climatic wind tunnel is used to perform the experimental tests. The clear up pattern developed utilising the vehicle defroster system is digitally captured and compared to the clear up pattern developed utilising the electrical heated windshield. Moreover, the clear up pattern developed using the vehicle defroster system is used to validate a computational model.

This paper describes an investigation into the fluid flow and heat transfer on the windshield as well the effect of the air discharge from the defroster vents on passenger comfort. The investigation is both experimental and computational. Full-scale tests are conducted on a current vehicle model using non-intrusive diagnostic methods. The results presented are from numerical simulations validated by experimental measurements. The numerical predictions compare well with the experimental measurements. The locations of maximum velocity and pressure, as well as width and length of re-circulation regions, are correctly predicted.

Hover and ground-effect tests were conducted with the Lockheed-Martin Large Scale Powered Model (LSPM) during June-November 1995 at the Outdoor Aerodynamics Research Facility (OARF) located at NASA Ames Research Center. This was done in support of the Joint Strike Fighter (JSF) Program being lead by the Department of Defense. The program was previously referred to as the Joint Advanced Strike Technology (JAST) Program. The tests at the OARF included: engine thrust calibrations out of ground effect, measurements of individual nozzle jet pressure decay characteristics, and jet-induced hover force and moment measurements in and out of ground effect. The engine calibrations provide data correlating propulsion system throttle and nozzle settings with thrust forces and moments for the bare fuselage with the wings, canards, and tails removed. This permits measurement of propulsive forces and moments while minimizing any of the effects due to the presence of the large horizontal surfaces.

Pressure-sensitive paint (PSP) technology is a technique used to experimentally determine surface pressures on models during wind tunnel tests. The key to this technique is a specially formulated pressure-sensitive paint that responds to, and can be correlated with the local air pressure. Wind tunnel models coated with pressure-sensitive paint are able to yield quantitative pressure data on an entire model surface in the form of light intensity values in recorded images. Quantitative results in terms of pressure coefficients (Cp) are obtained by correlating PSP data with conventional pressure tap data. Only a small number of surface taps are needed to be able to obtain quantitative pressure data with the PSP method. This technique is gaining acceptance so that future automotive wind tunnel tests can be done at reduced cost by eliminating most of the expensive pressure taps from wind tunnel models.