High Speed Single Cavity Rig With Axial Throughflow of Cooling Air: Rig Structure and Periphery

Diemel, Eric; Odenbach, Stefan; Uffrecht, Wieland; Villazon, Jose Rey; Valencia, Antonio Guijarro; Reinecke, Mike

doi:10.1115/gt2019-91265

Cited by 9 publications

(5 citation statements)

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“…Owen and Long [1] provide a wide-ranging review of buoyancy-induced flow in rotating cavities. The relevant dimensionless parameters for aero-engine compressors are Gr (~10 13 ), Rez (~10 5 ), Ro (~10 0 ), and β∆T (~10 -1 ). This review was extended by Luberti et al [2], including discussion of the most recent and relevant experimental work from the universities at Sussex [3], Dresden [4,5] and Beihang [6].…”

Section: Literature Reviewmentioning

confidence: 99%

“…The relevant dimensionless parameters for aero-engine compressors are Gr (~10 13 ), Rez (~10 5 ), Ro (~10 0 ), and β∆T (~10 -1 ). This review was extended by Luberti et al [2], including discussion of the most recent and relevant experimental work from the universities at Sussex [3], Dresden [4,5] and Beihang [6]. Luberti et al [7] showed that the radial distribution of temperature has a significant effect on the disc growth and consequently on the blade clearance in a compressor.…”

Section: Literature Reviewmentioning

confidence: 99%

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Measurement and Analysis of Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Jackson

Luberti

Tang

et al. 2021

Journal of Engineering for Gas Turbines and Power

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The flow inside cavities between co-rotating compressor discs of aero-engines is driven by buoyancy, with Grashof numbers exceeding 1013. This phenomenon creates a conjugate problem: the Nusselt numbers depend on the radial temperature distribution of the discs, and the disc temperatures depend on the Nusselt numbers. Furthermore, Coriolis forces in the rotating fluid generate cyclonic and anti-cyclonic circulations inside the cavity. Such flows are three-dimensional, unsteady and unstable, and it is a challenge to compute and measure the heat transfer from the discs to the axial throughflow in the compressor. In this paper, Nusselt numbers are experimentally determined from measurements of steady-state temperatures on the surfaces of both discs in a rotating cavity of the Bath Compressor-Cavity Rig. The data are collected over a range of engine-representative parameters and are the first results from a new experimental facility specifically designed to investigate buoyancy-induced flow. The radial distributions of disc temperature were collected under carefully-controlled thermal boundary conditions appropriate for analysis using a Bayesian model combined with the equations for a circular fin. The Owen-Tang buoyancy model has been used to compare predicted radial distributions of disc temperatures and Nusselt numbers with some of the experimentally determined values, taking account of radiation between the interior surfaces of the cavity. The experiments show that the average Nusselt numbers on the disc increase as the buoyancy forces increase. At high rotational speeds the temperature rise in the core, created by compressibility effects in

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Section: Literature Reviewmentioning

confidence: 99%

Section: Literature Reviewmentioning

confidence: 99%

Measurement and Analysis of Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Jackson

Luberti

Tang

et al. 2021

Journal of Engineering for Gas Turbines and Power

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show abstract

“…A recent single cavity rig described by Diemel et al [5] aims to measure the cavity surface temperature, surface pressure, core temperature and inlet swirl angle over a range of nondimensional parameters. The rig features high rotational speed with Reϕ ~ 1.4×10 7 and Gr < 10 14 .…”

Section: Literature Reviewmentioning

confidence: 99%

“…However, although it is a three-cavity rig, disc and shroud temperatures are measured only in the central cavity; the surfaces of the outer cavities are thermally insulated to avoid the ambiguity (noted above) in the calculation of the disc Nusselt numbers associated with uninsulated discs. This is an important design feature directly supporting the use of the fin model [12], which implicitly assumes there are no axial temperature differences within the disc; the zero axial temperature gradient is equivalent University of Sussex [10,11] TU Dresden [5] University of Sussex [7,8] TU Dresden [2,3] Aachen University [13] MTU Aero Engines [14] Beihang University [4] 𝑅𝑒 4 to a symmetry axis on the insulated surface. The rig includes other features not found in (or not reported for) the rigs described in Section 2.…”

Section: Design Of the Rigmentioning

confidence: 99%

Design and Testing of a Rig to Investigate Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Luberti

Patinios

Jackson

et al. 2021

Journal of Engineering for Gas Turbines and Power

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The change in compressor blade-tip clearance across the flight cycle depends on the expansion of the rotor, which in turn depends on the temperature and stress in the discs. The radial distribution of temperature is directly coupled to the buoyancy-driven flow and heat transfer in the rotating disc cavities. This paper describes a new test rig specifically designed to investigate this conjugate phenomenon. The rig test section includes four rotating discs enclosing three cavities. Two discs in the central cavity are instrumented with thermocouples to provide the radial distribution of temperature; the two outer cavities are thermally insulated to create appropriate boundary conditions for the heat transfer analysis. An axial throughflow of air is supplied between a stationary shaft and the bore of the discs. The temperature of the throughflow air is measured by thermocouples in rakes upstream and downstream of the central cavity. For a cold throughflow, the outer shroud of the central cavity is heated. Two independently-controlled radiant heaters allow differential shroud temperatures for the upstream and downstream discs, as found in aero-engine compressors. Alternatively, the throughflow can be heated above the shroud temperature to simulate the transient conditions during engine operation where stratified flow can occur inside the cavity. The rig is designed to operate in conditions where both convective and radiative heat transfer dominate; all internal surfaces of the cavity are painted matt black to allow the accurate calculation of the radiant heat transfer.

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“…Compressor cavities rigs have been built to simulate disc heat transfer under different operating conditions, with disc temperatures measured using embedded thermocouples. For example, the Universities of Sussex 1-3 and Bath [4][5][6] and TU Dresden [7][8][9] have all used K-type thermocouples in titanium discs to measure radial distributions of temperature. Given an appropriate model of heat transfer, heat fluxes can be calculated from these measurements.…”

Section: Introductionmentioning

confidence: 99%

Use of Bayesian statistics to calculate transient heat fluxes on compressor disks

et al. 2022

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Future gas turbine engines require improved understanding of the heat transfer between compressor discs and air in compressor cavities under transient operating conditions. Calculation of transient heat fluxes from temperature measurements on compressor discs is a typical ill-posed inverse problem where small uncertainties of measurements can lead to large uncertainties of the calculated fluxes. This paper develops a Bayesian model for the heat flux to reduce the adverse nature of the problem by using a Gaussian prior distribution with Matérn covariance. To efficiently find the maximum a posterior (MAP), a neural network was used to solve the heat equation for compressor discs for any choice of parameters, allowing fast evaluation of the solution to the forward model for any heat flux of interest. The power of the Bayesian model is first demonstrated using numerically-simulated data. Subsequently, the model is used to calculate fluxes from measurements of transient temperature collected from the Compressor Cavity Rig at the University of Bath. The fluxes for four transient cycles were calculated and the results show that, at low rotational Reynolds number, the flow and the heat transfer in the closed cavity were initially dominated by buoyancy effects and then became stratified. At the highest Rotational Reynolds number, buoyancy-induced flow dominated the entirety of the transient process due to significant frictional heating at the periphery of the rig. The calculated fluxes present evidence for future theoretical and computational modelling of transient disc heat transfer, and the Bayesian model provides guidance for transient temperature data analysis.

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High Speed Single Cavity Rig With Axial Throughflow of Cooling Air: Rig Structure and Periphery

Cited by 9 publications

References 0 publications

Measurement and Analysis of Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Measurement and Analysis of Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Design and Testing of a Rig to Investigate Buoyancy-Induced Heat Transfer in Aero-Engine Compressor Rotors

Use of Bayesian statistics to calculate transient heat fluxes on compressor disks

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