An efficient finite element analysis/computational fluid dynamics (FEA/CFD) thermal coupling technique has been developed and demonstrated. The is achieved by an iterative procedure between FEA CFD calculations. Communication calculations ensures continuity of temperature heat flux. In the procedure, simulation treated as unsteady for a given transient cycle. To speed up coupling, steady are employed, considering that flow time scales much shorter than those solid conduction therefore...

Experimental measurements from a new single stage turbine are presented. The has 26 vanes and 59 rotating blades with design point expansion ratio of 2.5 vane exit Mach number 0.96. A variable sealing flow is supplied to the disk cavity upstream rotor then enters annulus through simple axial clearance seal situated on hub between stator rotor. Measurements at wall just downstream show degree circumferential pressure variation. Further in indicate strength swirling cavity, effects mainstream...

Unsteady flow dynamics in turbine rim seals are known to be complex and attempts accurately predict the interaction of mainstream with secondary air system cooling flows using computational fluid (CFD) Reynolds-averaged Navier–Stokes (RANS) turbulence models have proved difficult. In particular, published results from RANS over-predicted sealing effectiveness seal, although their use this context continues common. Previous studies ascribed discrepancy failure model structures a scale greater...

The accuracy of computational fluid dynamics (CFD) for the prediction flow and heat transfer in a direct preswirl system is assessed through comparison CFD results with experimental measurements. Axisymmetric three-dimensional (3D) sector models are considered. In 3D models, nozzles or receiver holes represented as axisymmetric slots so that steady state solutions can be assumed. A number commonly used turbulence tested three different codes, which were able to capture all significant...

Abstract Understanding and modeling of main annulus gas ingestion through turbine rim seals is considered advanced in this paper. Unsteady three-dimensional computational fluid dynamics (CFD) calculations results from a more elementary model are presented compared with experimental data previously published by Hills et al. (1997). The most complete CFD includes both stator rotor the interdisk cavity. k-ε turbulence standard wall function approximations assumed which was constructed...

Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made recent years. CFD is regularly used industry assessment air systems, the performance basic axisymmetric rotor/rotor stator/rotor disc cavities with radial throughflow largely understood documented. Incorporation three-dimensional geometrical features calculation unsteady flows are becoming commonplace. Automation CFD, coupling thermal models solid...

This paper describes the work done to achieve high parallel performance for an unstructured, unsteady turbomachinery computational fluid dynamics (CFD) code. The aim of described here is be able scale problems thousands processors that current and future machine architectures will provide. CFD code in design use industry also used as a research tool at number universities. High scalability has been achieved range test cases, from steady-state hexahedral mesh cases fully unstructured cases....

SUMMARY Conjugate heat‐transfer problems are typically solved using partitioned methods where fluid and solid subdomains evaluated separately by dedicated solvers coupled through a common boundary. Strongly schemes for transient analysis require to be many times each time step until convergence steady state. In practical situations, fairly simple frequently employed fixed‐point iteration process is rather ineffective; it leads large number of iterations per consequently long simulation...

Large-eddy simulations (LES) of wall bounded, low Mach number turbulent flows are conducted using an unstructured finite-volume solver the compressible flow equations. The numerical method employs linear reconstructions primitive variables based on least-squares approach Barth. standard Smagorinsky model is adopted as subgrid term. artificial viscosity inherent to spatial discretization maintained possible reducing dissipative contribution embedded in approximate Riemann minimum necessary....

A high-order numerical method is employed to investigate flow in a rotor/stator cavity without heat transfer and buoyant rotor/rotor cavity. The tool used employs spectral element discretization two dimensions Fourier expansion the remaining direction, which periodic corresponds azimuthal coordinate cylindrical coordinates. approximation uses Galerkin discretize governing equations, but polynomials within each obtain accuracy. second-order, semi-implicit, stiffly stable algorithm for time...

This paper presents numerical simulations of the unsteady flow interactions between main annulus and disc cavity for an axial turbine. The show influence asymmetries (vane wakes, blade potential effect), appearance rim seal instabilities. generation secondary frequencies due to non-linear is observed, possibility further low frequency effects resonance noted. computations are compared experimental results, looking at tracer gas concentration mass-flows. Results analysed investigate on...

This paper presents the transient aerothermal analysis of a gas turbine internal air system through an engine flight cycle featuring multiple fluid cavities that surround HP disk and adjacent structures. Strongly coupled fluid-structure thermal interaction problems require significant computational effort to resolve nonlinearities on interface for each time step. Simulation times may grow impractical if domains are included in analysis. A new strategy is employed decrease cost Significantly...

Flow and heat transfer in an aero-engine compressor disk cavity with radial inflow has been studied using computational fluid dynamics (CFD), large eddy simulation (LES), coupled fluid/solid modeling. Standalone CFD investigations were conducted a set of popular turbulence models along 0.2 deg axisymmetric 22.5 discrete sector models. The overall agreement between the predictions is good, solutions are comparable to established integral method solution major part cavity. LES demonstrates...

This paper considers the coupling of a finite element thermal conduction solver with steady, volume fluid flow solver. Two methods were considered for passing boundary conditions between two codes — transfer metal temperatures and either convective heat fluxes or coefficients air temperatures. These have been tested on simple rotating cavity test cases also more complex real engine example. Convergence rates compared. Passing was found to give quickest convergence. The coupled method gave...

Abstract In a gas turbine, ingestion of hot into the high-pressure turbine disc cavities could cause metal overheat. To prevent this, cool air is taken from compressor and ejected through cavities. However, this sealing flow also reduces overall efficiency, compromise has to be found between level tolerated losses. Recent advances made in applying Computational Fluid Dynamics such configurations are presented, with aim better understanding physical phenomena providing reliable design tools....

Use of computational fluid dynamics (CFD) to model the complex, 3D disk cavity flow and heat transfer in conjunction with an industrial finite element analysis (FEA) turbine thermomechanical response during a full transient cycle is demonstrated. The FEA CFD solutions were coupled using previously proposed efficient coupling procedure. This iterates between calculations at each time step solution ensure consistency temperature flux on appropriate component surfaces. 2D representation high...

Unsteady flow dynamics in turbine rim seals are known to be complex and attempts accurately predict the interaction of mainstream with secondary air system cooling flows using CFD RANS turbulence models have proved difficult. In particular, published results from over-predicted sealing effectiveness seal, although their use this context continues common. Previous authors ascribed discrepancy failure model structures a scale greater than can captured small sector typically used. This paper...

In compressor inter-disc cavities with a central axial throughflow it is known that the flow and heat transfer strongly affected by buoyancy in centrifugal force field. As step towards developing CFD methods for such flows, buoyancy-driven flows under gravity closed cube sealed rotating annulus have been studied. Numerical simulations are compared experimental results of Kirkpatrick Bohn (1986) et al (1993). Two different codes used shown to agree stationary problem. Unsteady show good...

This paper examines the application of a newly developed code, which couples commercial computational fluid dynamics (CFD) code (FLUENT) directly to an in-house finite element solver used by Rolls-Royce plc. The coupling is achieved passing metal temperatures from define CFD boundary conditions, and then heat fluxes resulting solutions back model. method was applied real engine test case, modelling pre-swirl system Trent 500 aero engine. initial phase analysis axisymmetric whole model two...

The design and optimization of an efficient internal air system a gas turbine requires thorough understanding the flow heat transfer in rotating disc cavities. present study is devoted to numerical modeling cylindrical cavity with radial inflow comparison available experimental data. simulations are carried out axisymmetric 3-D sector models for various inlet swirl rotational Reynolds numbers up 1.2 × 106. pressure coefficients Nusselt compared data integral method solutions. Two popular...

Measurements and analysis for a pre-swirl cooling air delivery system are reported here. The experimental rig used is representative of aero-engine conditions, having 18 nozzles, 72 receiver holes, capable speeds up to 11 000 rpm, giving differences between total temperature upstream the nozzles relative measured in holes 26K. Pressure measurements reported. An elementary model developed calculation temperature. This accounts nozzle velocity coefficient, moments on stationary rotating...

This paper reports results from numerical simulations of the flow in pre-swirl cooling air delivery systems. Two different systems have been investigated corresponding to experimental rigs for which measured data is available. The are representative aero-engine conditions. difference performance two has addressed. nozzles and chambers separately. For chamber a simplified model, nozzle replaced by slot, used reduce computational effort required. Nevertheless good agreement with measurements....

The optimization of heat transfer between fluid and metal plays a crucial role in gas turbine design. An accurate prediction temperature for each component can help to minimize the coolant flow requirement, with direct reduction corresponding loss thermodynamic cycle. Traditionally, industry solid simulations are conducted separately. stresses temperatures, generally based on finite element analysis, requires definition thermal model whose reliability is largely dependent validity boundary...

Design of pre-swirl systems is important for the secondary air cooling system gas turbine engines. In this paper, three nozzles, a cascade vane and two drilled nozzles are analysed their performances compared. The considered straight nozzle an aerodynamically designed nozzle. CFD analyses presented stand-alone 3D sector models at engine operating conditions near to maximum power condition rotational Reynolds number (Reφ) up 4.6 ! 107. Nozzle performance characterised by discharge coefficient...