A nonlinear harmonic methodology has been developed to calculate unsteady viscous flows through turbomachinery blades. Flow variables are decomposed into time-averaged and perturbations, resulting in the equations with extra stress terms depending on perturbations. An efficient evaluation of an flowfield is obtained by solving first-order equations. The interactions between perturbations were included a strong coupling approach. basic computational was applied two-dimensional Navier-Stokes...

In this paper, high and low speed tip flows are investigated for a high-pressure turbine blade. Previous experimental data used to validate computational fluid dynamics (CFD) code, which is then study the heat transfer in cascades. The results show that at engine representative Mach numbers, flow predominantly transonic. Thus, compared with flow, affected by reductions both heat-transfer coefficient recovery temperature. numbers region (M>1.5) lead large local variations Significant...

In this paper, the transonic flow pattern and its influence on heat transfer a high-pressure turbine blade tip are investigated using experimental computational methods. Spatially resolved data obtained at conditions representative of single-stage (Mexit=1.0, Reexit=1.27×106, gap=1.5% chord) transient infrared thermography technique within Oxford high speed linear cascade research facility. Computational fluid dynamics (CFD) predictions conducted Rolls-Royce HYDRA/PADRAM suite. The CFD...

A closely combined experimental and computational fluid dynamics (CFD) study on a transonic blade tip aerothermal performance at engine representative Mach Reynolds numbers (Mexit=1,Reexit=1.27×106) is presented here its companion paper (Part II). The present considers surface heat-transfer distributions surfaces suction pressure-side (near-tip region). Spatially resolved data are measured using infrared thermography transient techniques within the Oxford University high speed linear cascade...

The primary requirement for high pressure turbine heat transfer designs is to predict blade metal temperature. There has been a considerable recent effort in developing coupled fluid convection and solid conduction (conjugate) prediction methods. They are, however, confined steady flows. In the present work, new approach conjugate analysis periodic unsteady flows proposed demonstrated. First, simple model carried out quantify huge disparity time scales between conduction, implications of...

The adjoint method for blade design optimization will be described in this two-part paper. main objective is to develop the capability of carrying out aerodynamic blading shape a multistage turbomachinery environment. To end, an mixing-plane treatment has been proposed. In first part, numerical elements pertinent present approach described. Attention paid exactly opposite propagation characteristics against physical flow characteristics, providing simple and consistent guidance development...

The high pressure (HP) turbine is subject to inlet flow nonuniformities resulting from the combustor. A lean-burn combustor tends combine temperature variations with strong swirl and, although considerable research efforts have been made study effects of a circumferential nonuniformity (hot-streak), there relatively little known about interaction between two. This paper presents numerical investigation transonic test HP stage MT1 behavior under combined influence and hot-streak. in house...

Recent studies have demonstrated that the aerothermal characteristics of turbine rotor blade tip under a transonic condition are qualitatively different from those low-speed subsonic condition. The cooling injection adds further complexity to over-tip-leakage (OTL) flow behavior and performance, particularly for commonly studied shroudless configurations such as squealer tip. However there has been no published experimental study cooled squealer. present investigates effect on through...

Rotating-stall inception in axial-e ow compressors has been studied computationally using a quasi-threedimensional time-marching Navier ‐ Stokes method with mixing-length turbulence model. Of particular interest was the effect of external circumferential disturbances corresponding to inlet stagnation pressure distortions and rotor/stator blade interactions. The present results show that rotating stall onset patterns terms number cells speeds were ine uenced by small stationary or rotational...

Qualitatively different heat transfer characteristics between a transonic blade tip and subsonic one have recently been discovered. High-resolution experimental data can be acquired for blade-tip research using high-speed linear cascade. A combined computational fluid dynamics study on several high-pressure turbine configurations is conducted to understand the flow physics in both stationary moving casing setups. Extensive tests measuring aerodynamic loss performed squealer at...

At engine representative flow conditions a significant portion of over high pressure turbine blade tip is transonic.In the present work, choking behavior and its implications on over-tip leakage loss generation are computationally analyzed.An extensively developed RANS code (HYDRA) adopted.Firstly speed linear cascade validation case introduced, computations compared with experimental data to identify establish capability in predicting aerodynamics losses for transonic tip.The computational...

<title>Abstract</title> In power systems, insulators are critical components whose damage or failure can lead to equipment malfunctions interruptions, presenting significant challenges for operation and maintenance. Traditional manual inspection methods inefficient prone human error, failing meet the high-precision high-efficiency demands required fault detection in modern systems. To address this, present study proposes combining YOLOv8 algorithm with AIFI technology intelligent diagnosis...

A quasi-three-dimensional time-linearized Euler method has been developed to compute unsteady flows around oscillating blades. In the baseline method, flow is decomposed into a steady plus linear harmonically varying flow. Both equations and perturbation are solved using pseudo-time-marching method. Based upon this novel nonlinear harmonic developed. Due nonlinearity of aerodynamic governing equations, time-averaging generates extra “unsteady stress” terms. These effects included by strongly...

A nonlinear harmonic methodology is adopted to analyze interactions between adjacent stages in multi-stage compressors. Of particular interest are the effects of circumferential “aperiodic” distributions and relative positioning (‘clocking’) blades. The main feature present approach that both aperiodic clocking very efficiently included with “steady” disturbances. Consequently, a single run solver using single-passage domain can produce whole annulus unsteady time-averaged flow field. In...

An efficient non-linear harmonic methodology has been developed for predicting unsteady blade row interaction effects in multistage axial flow compressors. Flow variables are decomposed into time averaged and perturbations, resulting equations with deterministic stress terms depending on the perturbation. The between field perturbations included by a simultaneous pseudotime integration approach, leading to strongly coupled solution. stator/rotor interface treatment follows flux...

For high pressure turbine heat transfer designs, a primary requirement is to predict blade metal temperature. There has been considerable recent effort in developing coupled fluid convection and solid conduction (conjugate) prediction methods. They are so far, however, confined steady flows. In the present work, new approach conjugate analysis for periodic unsteady flows of practical interest proposed demonstrated. This paper starts with simple model quantify huge disparity time scale...

The present study considers spatially resolved surface heat transfer coefficients and adiabatic wall temperatures on a turbine blade tip in linear cascade under transonic conditions. Five different measurement processing techniques using infrared thermography are considered compared. Three transient methods use the same experimental setup, heater mesh to provide near-instantaneous step-change mainstream temperature, employing an camera measure temperature. These three data but determine...

This paper presents an experimental and numerical investigation of the aero-thermal performance uncooled winglet tip, under transonic conditions. Spatially-resolved heat transfer data, including tip surface near side walls, are obtained using transient infrared thermography technique within Oxford High Speed Linear Cascade test facility. CFD predictions also conducted Rolls-Royce HYDRA suite. Most spatial variations on well-captured by solver. The flow pattern its influence analyzed, which...

A basic attribute for turbine blade film cooling is that coolant injected should be largely passively convected by the local base flow. However, effective working of conventional wisdom may compromised when injection strongly interacts with Rotor tip a transonic high-pressure (HP) one such challenging regions which understanding relevant aerothermal behavior as basis heat transfer/cooling design lacking. The need to increase our and predictability high-speed has been underlined some recent...

Conventional time-linearized harmonic methods using a pseudo-time-marching technique often exhibit solution divergence behavior for highly loaded conditions with flow separation. This is attributed to the growth of linear instabilities associated small-scale limit-cycle oscillations base-flow state. In present work, an alternative formulation adopted modeling disturbances intention harness nonlinearity as means stabilization while achieving same computational efficiency conventional model....

Increasing aerothermal and aero-elastic performance requirements constraints are closely linked in modern blading designs. There is thus a need for more concurrent interaction between the disciplines at earlier stages of design process. Presented this paper development, validation, demonstration adjoint approach to aerodynamic optimizations. A nonlinear harmonic phase solution method adopted solve unsteady Reynolds-averaged Navier–Stokes equations. The flow field response terms both mean...

This paper presents an experimental and numerical investigation of the aerothermal performance uncooled winglet tip, under transonic conditions. Spatially resolved heat transfer data, including tip surface near-tip side-walls, are obtained using transient infrared thermography technique within Oxford high speed linear cascade test facility. Computational fluid dynamics (CFD) predictions also conducted Rolls-Royce HYDRA suite. Most spatial variations on well-captured by CFD solver. The flow...

In the present work, effect of coolant injection on over-tip-leakage (OTL) flow and squealer designs has been investigated in a transonic regime. After an experimental verification computational tool adopted for capturing characteristics, series quasi-three-dimensional (3D) analyses were carried out to reveal understand cooling jet—OTL interaction at various hole locations inclination angles. The results indicate that performance rankings between flat tip might be altered by addition...