Aerodynamic study for the flow through cascade blades of gas turbine with vibration effect: a review

Abstract

A research survey on aerodynamic with/without vibration effect and investigations for turbine components of gas turbine engines is presented. Experimental and numerically predicted results are presented from investigations undertaken over the past 70 years. The aerodynamics between the turbine blades is very important as it determines the overall system performance. The importance of aerodynamics is being in the pressure distribution above and below each airfoil, the locations of the vortices occurring, their number, distribution, direction, and shedding, and the determination of the regions of fluid separation from the wall that is directly related to the fluid velocity. Many ranges of vibration that affect different bodies were taken, and some of these ranges were small (10-200 Hz), and others had large ranges from 1.5 to 10 KHz. therefore the result evolution and shedding of vortices corresponding to the deformation in fluid structure depends on the Reynolds number and value of amplitude and frequency for vibration. The Mach number is a clear indicator to represent these characteristics. It also includes studying the theoretical methods used and simulations of the researchers’ aerodynamics, the accuracy of the results reached, the representation of the body contour and the diagrams for each of the pressure and Mach number, the pressure (Cp ) and lift (CL ) coefficients, and their amount of change occurring at each location of the airfoil. The importance of the above topics has motivated us to prepare a comprehensive review mostly of the aerodynamics of turbine blades and the effect of the vibration on the flow. The main concepts of aerodynamics, such as Cp and CL as well as vibration frequency are presented. It also highlights the performance of the turbine blades as a result of vibration

Some effects of non-axisymmetric tip clearance layout on axial compressor aerodynamics

“…[18][19][20] When tip clearance flows are involved, grids within the clearance should be paid special attention to. As unsteady simulations are commonly conducted to simulate flows such as fluctuation of leakage flow, rotating instability, 21 and flow distortion, 22 the setting of time step must meet the requirements of independence and capturing unsteady features. An et al 23 conducted a series of unsteady numerical investigations on the compressor tip flow unsteadiness, observing the flow conditions can be divided into stable without oscillations and flow oscillation conditions, and the transition between them is essential to explain the unsteady mechanism.…”

“…18–20 When tip clearance flows are involved, grids within the clearance should be paid special attention to. As unsteady simulations are commonly conducted to simulate flows such as fluctuation of leakage flow, rotating instability, 21 and flow distortion, 22 the setting of time step must meet the requirements of independence and capturing unsteady features. An et al.…”