Robust and Accurate Transient Multi-Hole Traverses: A Physical Approach Using Laplace Transform

Abstract A novel method for faster pneumatic wake loss measurements of steady flow fields through transient traversing is proposed and evaluated. This method accounts for dynamic effects of the pneumatic measurement chain with a transfer function of first and second order. By running two opposing pressure measurements of the same flow gradient from opposing directions and modeling the pneumatic system with a transfer function in the Laplace domain, the true local pressure distribution can be calculated iteratively without any a-priori knowledge of the system itself. This paper discusses the new approach and presents the benefits compared to existing techniques. The novel approach is validated by various wake flow test cases at low speed and in transonic flow and compared to the output of existing techniques. It is shown that the novel approach is able to deliver accurately reconstructed pressure distributions as well as relevant physical quantities such as the time constant and damping ratio of the pneumatic system.