Measurement of aerodynamic heating of micro-scale rotational shearing flow and its heat flux identification

This study conducted the experimental investigation of aerodynamic heating of Micro-scale Rotational Shearing Flow with Axial Limited-Length (MRSFALL). The temperature rise of the stator is captured by the high response thermocouples. The eccentricity ratio and clearance height are guaranteed by means of instantaneous trajectory and torsion monitoring of the rotator. The result shows that the maximum temperature rise takes place upstream of the minimum clearance height along circumferential direction. The distribution of temperature rise presents asymmetric curve along axial direction, and peak value occurs near the dimensionless axial position of −0.18. The effect of aerodynamic heating becomes notable as the rotational speed is larger than 3 × 10⁴ r/min. The effect of end leakage and the viscous dissipation have great impact on temperature rise of MRSFALL. More specially, the peak value of temperature rise at dimensionless clearance height of 0.0080 is larger than the case at dimensionless clearance height of 0.0044. Furthermore, when the eccentricity ratio is too large, the viscous dissipation is induced, and the additional temperature rise is achieved. The heat flux identification of shear flow has been realized by Sequential Function Specification Method (SFSM) and its estimation of thermal load has been given. The heat flux induced by the aerodynamic heating in this study varies from 950 W/m² to 1330 W/m².