| Abstract: | Phase-change coatings have been applied to the axial-clearance rotor-stator cavity for the estimation of the transient heat transfer characteristics of the surface of the rotating disc. The tests were conducted for an air mass flow coefficient Cw = 1220, a gap ratio G = 0.1, an axial-clearance ratio Gca = 0.05 and for rotational Reynolds numbers of Re? = 1 × 105 and 2 × 105. The phase-change coating used had a melting point of 38°C. From a video recording of the transient movement of the melt-line on the rotor (coated with the phase-change material) blown with heated air, it was possible to compute the heat transfer coefficients. The data reduction was made using the ‘semi-infinite slab’ approximation to the governing one-dimensional transient heat conduction equation. |
