Inertia and expansion level impact on flow development at various duct sections. (2022) - Attar .M, MashtaqAhamed
Abstract: This study aims to investigate the effect of expansion on the flow of the duct. The pipe diameter is 18 mm, and tests were done at Mach 1.8, 2.0, and 3.0. When there is an adverse pressure gradient at the nozzle exit, the wall pressure attains high values due to the oblique shock. For this case, once the flow control technique is used, the pressure reduces in the duct. At the design nozzle pressure ratio (NPR), the wall pressure results show a similar pattern for Mach 1.8 and 2.0. Among them, marginal variations are seen due to the change in the duct length, impact of the backpressure, and interaction of the shock waves. However, at tube section 2D, the stream continued fastened to the wall tube. The stream pattern with and without control are similar. There is a minimal variation in the duct's stream pattern, and the normalized wall pressure fluctuations are large. Despite the stream being fastened to the tube's wall for the lowest duct length, the pipe pressure attains the ambient pressure value due to the freestream pressure impact.