关键词: 层流机翼, 转捩探测, 在线加热, 风洞试验, 飞行试验, 宽速域, 超声速, 跨声速

Abstract: A boundary layer transition detection technique by means of on-line heating coating is proposed for the verification requirements of transonic/supersonic laminar wings. The applicable speed range of transition detection is expanded by improving the signal-to-noise ratio and the experimental data reliability. The current status and the main shortcomings of the transition detection for transonic laminar wing in wind tunnel and flight test are summerized. A three layer electric heating coat structure is developed, and the preparation process of the insulation layer and the resistance coat layer presented. The total thickness of the heating coat can be controlled in 40-60 μm to reduce the influence of the heating coat on the boundary layer transition and pressure distribution. The first experiment was conducted in a transonic wind tunnel to measure the boundary layer transition on an airfoil. Compared with that of the traditional method, the temperature difference between the laminar and turbulent region measured by the electric heating technique was increased from 2 K to 4 K. The second experiment was conducted in a supersonic wind tunnel, where the transition location of a supersonic swept wing can be visualized with heating. The transition detection capability in the flow field of Mach number 0.3-2.0 was realized. On this basis, the transition detection technology scheme of flight tests is formed, and the detailed design schemes such as the power of the heating on the wing surface in the test section and the optical pod of the infrared camera are provided.

Key words: laminar wing, boundary transition detection, on-line heating, wind tunnel test, flight test, wide speed range, supersonic, transonic