Wall interference is one of the major obstacles to increase the model size and data accuracy. There have been many treatments for wall interference including interference correction and adaptive wall test section. The adaptive wall concept is an active means to remove wall interference and has been realized in two-dimensional steady flow testing. In order to be practiced in three-dimensional or unsteady testing, further research and development are required. The objective of this study is to suggest and verify a new adaptive wall model for unsteady two-dimensional test and steady three-dimension test.
In this study, wind tunnel and free air tests are simulated by the numerical computation of Euler equations. In order to compare the ability of reducing wall interference, two classical correction methods and one measured-boundary-condition method are applied to test section result. By those correction methods, wall interference are reduced significantly, but less effective than those by adaptive wall. For the two-dimensional steady flow, The adaptive wall's ability of eliminating wall interference are evaluated from the point of view of flow speed, also.
For two-dimensional unsteady flow, unsteady adaptation has never been realized until now. In the present study, practicable models are suggested and numerically verified to be effective in reducing unsteady wall interference. The necessary facts for their real application are discussed.
Recently, two-flexible-walled adaptive wall test section is concluded adequate for three-dimensional test. But proper location of target line and pressure holes are critical to its success. In this study, a new adaptive algorithm which dispenses target line and dependency of pressure hole distribution is suggested. The optimum wall shape is achieved by two variable optimization which is composed of two base streamlines. The wall interference is reduced well in the optimized result which is not sensitive to the base streamlines. So, base streamlines can be obtained from numerical computation in real application.
