ENVIRONMENTAL WIND TUNNEL FOR AUTOMOBILE

PURPOSE:To perform wind tunnel tests with a small air-current cross section, by forming the wall surface of a wind tunnel in such a streamline shape that can simulate the running state of a test car or the running state of another test car which is very similar to the first mentioned test car in shape and dimensions. CONSTITUTION:The streamline shape of a curved-surface cover 3 is previously approximated to a streamline 3' which is formed in the course of a wind tunnel test which can accurately simulate the running state of a test car 1 and by flow analysis, etc. Moreover, the shape of the curved surface of the cover 3 is formed so that the curved surface can follow the streamline three-dimensionally. Therefore, a state where the test car 1 is put in a uniform air flow can be realized, even when the cross section of the air flow 2 flowing into a measuring section is almost the same as that of the test car 1. If another test car 1' is similar to the test car 1 in shape and dimensions as shown in the figure, no much difference can be found between the shape of the streamline formed when the test car 1 is put in a uniform air current and the shape of the streamline formed when the test car 1' is put in the uniform air current. Therefore, the curved-surface cover 3 which is manufactured in accordance with the test car 1 can be used for the test car 1'. Accordingly, wind tunnel tests can be carried out with a small air-current cross section.