Passive Effusion Cooling in a Rectangular S-Bend Diffuser

The experimental study considered passive effusion cooling in an S-bend diffusing passage in which ambient cool air was drawn naturally into the S-bend passage with subatmospheric flow distributions. Seven-hole pressure probes were used to measure the test section’s inlet and outlet flow conditions which were used to evaluate the performance of the S-bend diffuser. Back-pressure, outlet flow-fields, and wall pressure distributions were investigated to study the effects of effusion cooling on the pressure recovery performance of the S-bend diffuser. The study revealed a substantial back-pressure penalty and wall pressure distribution alteration in the S-bend passage with full coverage effusion cooling. The outlet diffuser was shown to be not as effective with effusion cooling. The findings highlighted the importance of the design of effusion holes locations in complex flow passages.