The woven surface effect on the turbulent flow quantities of jet in crossflow

Woven surfaces are typically formed on ceramic matrix composites—potential materials for the next-generation turbine blades. Their unique weaving process creates macroscale groove-ridge structures on the surface. These structures have been confirmed to significantly influence the performance of jet in crossflow (JICF) cooling on turbine blades. However, the underlying flow mechanisms remain unclear. This study utilizes the refractive index matching (RIM) technique to eliminate light reflection and optical distortion in particle image velocimetry (PIV). It enables an investigation of the near-wall turbulent flow quantities in a JICF over a standard Plain-pattern woven surface. The results reveal that ridge structures on a woven surface amplify spatial flow fluctuation, increase near-wall swirling strength, and enhance turbulence production. The consumption of the jet is accelerated on a woven surface, and its interaction with the mainstream is strengthened. At a low velocity ratio VR = 0.25, the near-wall flow will deplete the jet rapidly and degrade the JICF cooling performance. While at a high velocity ratio VR = 1.00, it will promote near-wall flow mixing and benefit the JICF cooling. The RIM-PIV research elucidates the flow mechanisms underlying the previously reported multiplicated JICF cooling performance on woven surfaces and can provide theoretical foundations for optimizing the JICF cooling designs in woven blades.