低速风洞设计中的导流片损失问题

低速回流式风洞中拐角部位的流动损失占总损失的比重很大，该位置导流片绕流的流动状况对于流动损失有明显的影响。与常规的工程估算方法不同，风洞实验与数值计算相结合，并通过正交优化能够对不同工作条件下导流片流动及其性能指标的变化规律进行研究，对特定的导流片找到了最佳的工作条件。

Research on energy loss of guide vane in low-speed wind tunnel

Research is conducted on the energy loss of flow around a cascade of guide vanes in a low speed wind tunnel numerically and experimentally. With finite differential method and multigrid technology, the flow field around a cascade of bi arc vanes and SA070.61 vanes are calculated respectively. Orthogonal designing method is used to optimize the conditions from various representative combinations of factors. To verify the results of calculations and optimizations above ,and to reveal the variation of flow energy loss, flow visualization and total pressure measurement are carried out . For SA070.61 vane , which is designed according to an object pressure distribution, there exists an optimum incidence corresponding to a given solidity . Near respective optimum incidences, the flow around SA070.61 is preferable to that around bi arc guide vanes. Therefore, the momentum loss of flow is less correspondingly. In experiments the variation of flow is in agreement with results of numerical computations on lift to drag ratios and bending angles.