Comparison between Hot and Cold Flow Conditions of Turbine Cascade

Abstract

Flow quantities in the hot and cold flow conditions of a turbine cascade were compared at the same exit isentropic Mach and Reynolds numbers by three-dimensional flow simulations. In the hot flow condition, the total temperature at the inlet was 772 K, and the isothermal temperature of the blade was 540 K. In the cold flow condition, the total temperature at the inlet was 280 K, and the blade was adiabatic. As a result, the cold and hot flow conditions were similar in total and static density in the wake, total and static pressure, velocity, the thicknesses of the viscous and thermal boundary layers, and the amplitude and frequency of the vortex shedding. On the other hand, they were different in static density in the boundary layer, and total and static temperatures. Moreover, the Eckert-Weise effect was observed in the cold flow condition, while energy separation in the wake was observed in the hot flow condition.

A Review on Turbine Trailing Edge Flow

“…The predicted base pressure coefficients defined by Equation ( 2) agree fairly well with the experimental value, as well as with the one obtained from the VKI correlation [110]. The success of these simple models is attributed to the proper space-DDES [120,121]; experiments [21]; DDES [120,121]; DDES [123]; structured LES [118]; unstructured LES [118];…”

“…And relieving the Modeled Stress Depletion of DES by better addressing the URANS-LES migration in the grey area, will only partially alleviate the grid induced separation issue of these hybrid methods. All in all, the two DDES simulations of El-Gendi et al [120,121] and Wang et al [123] are also to be considered as unresolved, because of the previously mentioned cut-off misplacement. We shall return to this point later on.…”

“…1217 [120,121] and Wang et al [123] are also to be considered as unresolved, because of the previously 1218 mentioned cut-off misplacement. We shall return to this point later on.…”

“…Surprisingly, the difficult region of the unguided turning in the rear part of the suction side (0.6 < x/C ax < 0.8) where the shock wave turbulent boundary layer interaction occurs, is well predicted in a time averaged sense by all closures. experiments [21]; DDES 1258 [120,121]; DDES [123]; structured LES [118]; unstructured LES [118];…”

“…1265 [118] and Kopriva et al [67] (results not shown herein). In fact, when the simulations are performed 1266 with a steady-state approach there is no sudden pressure drop originated by the enrolment of the experiments [21]; DDES 1265 [120,121]; DDES [123]; structured LES [118]; unstructured LES [118]; 1266 unstructured LES [56].…”