Experimental study on hypersonic shock–body interaction between bodies in close proximity using translucent fast pressure- and temperature-sensitive paints

This work presents a successful implementation of fast-responding pressure- and temperature-sensitive paints for study of hypersonic shock–body interaction between stage separation bodies. Fast PSP and TSP were applied symmetrically on two adjacent surfaces with a minimum separation of 5 mm, and the time-resolved pressure and temperature fields were obtained in a Ma = 6 flow using the intensity-based approach. The technical barrier of limited optical access was overcome through the development of translucent paints that allowed back-illumination and imaging through a glass wall. The in situ calibration was generally sufficient to remove the temperature-induced error for cases with weak/mild shock impingement on the surface. For cases with strong shock impingement and large temperature gradient, temperature correction was applied on the PSP data based on the TSP results prior to the in situ calibration. The PSP results with temperature correction showed good agreement with the transducer data. The complex flow structures due to shock–body interaction were clearly visualized by PSP and TSP, which allowed detailed analysis on the effects of separation distance and inclined angle. Graphic abstract