Влияние вращения поверхности на эффективность пленочного охлаждения за отверстиями в траншее

Abstract

Представлены результаты компьютерного моделирования эффективности пленочного охлаждения за одним рядом отверстий в траншее в стационарных условиях и в условиях вращения в диапазоне изменения параметра вдува 0,5 ≤ m ≤ 2,0. Показано, что вращение охлаждаемой поверхности вызывает смещение потока и пиков локальной эффективности пленочного охлаждения. Однако, для исследованной конфигурации влияние параметров вращения на среднюю эффективность пленочного охлаждения незначительное.

The film cooling is the primary technique of external cooling of the blades of high-temperature gas turbines. Investigations of the film cooling efficiency and physical structure at the coolant supply through a single array of inclined round holes in the trench at stationary conditions and rotation is of great interest of experts in the field of gas turbine building. The film cooling was simulated using the commercial software ANSYS CFX 14 that is widely used in solution of different problems related to gas turbine thermo-gasdynamics. All computations were carried out using SST turbulence model the adequacy of which was confirmed in previous investigations s of the authors. The study was made in the range of blowing parameter m from 0.5 to 2.0. The influence of surface rotation on the film cooling efficiency was studied for rotational speed of the cooled surface n which is 0; 9500; 15000 rpm. The mainstream flow velocity was 400 m/s, the temperature of the mainstream flow and injected flow was 1100 ºС and 500 ºС, accordingly. The results of computer simulation of film cooling efficiency behind holes in trench are presented for stationary and rotation conditions. It was shown that the rotation of the cooled surface leads to displacement of flow lines and local peaks of the film cooling efficiency. However, for the given configuration influence of the investigated parameters on the average film cooling efficiency is insignificant in the range of blowing parameters studied.