METHOD FOR DETERMINING THE HEAT TRANSFER COEFFICIENT THROUGH THE WALL OF A CONVECTIVE COOL PART Russian patent published in 2019 - IPC G01N25/18 

FIELD: measurement technology.

SUBSTANCE: invention relates to thermophysical measurements and is intended to determining heat transfer coefficient in convectively cooled parts, for example, in gas turbine blades. A method for determining the heat transfer coefficient through a wall of a convectively cooled part is proposed, including immersion of investigated part into a melt of a high-heat-conducting metal overheated above its crystallization temperature, cooling the melt and the part to a crystallization temperature, expulsion of the part with a cooling medium with measuring the time of expulsion and the temperature of the medium at the entrance to the part, removing it from the melt and measuring the thickness of solidified metal crust with the subsequent calculation of the heat transfer coefficient. Moreover, in the part testing process when it is in the melt at the time τ₁ remove the first crust, and τ₁≥τ_c, where τ_c – stabilization time of temperature of the cooling medium at the entrance to the part. At the end of expulsion at time τ_P after extracting the part, thickness of the second crust is measured, then heat transfer coefficient is determined by the formula

,

where δ – the thickness of the second metal crust formed on the part surface over a period of time (τ_p – τ₁) when expulsion in a crystallizing melt; τ₁ – time of removal of the first crust; τ_p – the end time of the expulsion; L is the heat of crystallization; ρ – density of molten metal; T_cr – temperature of melt crystallization and T_v – temperature of the cooling medium.

EFFECT: improving the accuracy of heat transfer coefficient determination in convective cooled parts.

1 cl, 2 dwg