Numerical Analysis of Heat Pipe Turbine Vane Cooling

A numerical model was developed to simulate transient performance of a heat pipe turbine vane under typical gas turbine engine conditions. Curvilinear coordinates were used to describe the three-dimensional wall and wick heat conduction coupled with the quasi-one-dimensional vapor flow. A unique numerical procedure including two iterative “estimate-correction” processes was proposed to efficiently solve the governing equations along with the boundary conditions. Comparisons with experimental results validated the numerical model and the solution method. A detailed numerical simulation of the heat pipe vane’s transient performance indicated the benefits of incorporating heat pipe vane cooling as well as the areas where precautions should be taken while designing heat pipe vanes.

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Transient Performance of Heat Pipes Using Nanofluids

Volume 11: Heat Transfer and Thermal Engineering ◽

10.1115/imece2020-23463 ◽

2020 ◽

Author(s):

Mahboobe Mahdavi ◽

Amir Faghri

Keyword(s):

Numerical Model ◽

Pressure Drop ◽

Response Time ◽

Thermal Resistance ◽

Heat Pipe ◽

Volume Concentration ◽

Heat Pipes ◽

Operating Conditions ◽

Vapor Flow ◽

Transient Performance

Abstract In the present works, a comprehensive transient numerical model was developed to evaluate the effect of nanofluid on the transient performance of heat pipes. The numerical model solves for compressible vapor flow, the liquid flow in the wick region, and the energy equations in the vapor, wick and wall. The distinctive feature of the model is that it can uniquely determine the heat pipe operating pressure based on the physical and operating conditions of the system. Three nanoparticle types were considered: Al2O3, CuO, and TiO2. The effects of the concentration of nanoparticles (5%, 10%, 20% and 40%) were investigated on the heat pipe response time, thermal resistance, and pressure drop under various operating conditions. The results showed that the use of nanofluid decreased the response time of the heat pipe by the maximum of 27%. It was also discovered that the thermal resistance decreased significantly with an increase in the volume concentration. A maximum reduction of 84%, 82% and 78% in thermal resistance was obtained for Al2O3, CuO, and TiO2, respectively. In addition, the effect of nanoparticles on the liquid pressure drop highly depends on the nanoparticle type and volume concentration.

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A Parametric Study of Heat Pipe Turbine Vane Cooling

Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration ◽

10.1115/97-gt-443 ◽

1997 ◽

Cited By ~ 2

Author(s):

Z. J. Zuo ◽

A. Faghri ◽

L. Langston

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Parametric Study ◽

Heat Transfer Performance ◽

Three Dimensional ◽

Working Fluid ◽

Vapor Flow ◽

Transfer Performance ◽

Transfer Coefficients ◽

Turbine Vane

This work investigates the effects of various parameters (geometric dimensions, working fluid, external heating and cooling conditions) on heat transfer performance of the heat pipe turbine vane. This parametric study is based on a numerical model which includes an one-dimensional vapor flow and a three-dimensional wall heat conduction. Heat transfer performance of the heat pipe turbine vane is represented by several parameters including the overall heat transfer coefficient, the temperature ratio, the cooling ratio and the ratios of performance limitations. It is shown that these performance parameters are sensitive to geometric dimensions, working fluid, and external heat transfer coefficients of the heat pipe turbine vane. Information resulting from this study can be used as guidance for design, test and operation of the heat pipe turbine vane.

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Transient Multidimensional Analysis of Nonconventional Heat Pipes With Uniform and Nonuniform Heat Distributions

Journal of Heat Transfer ◽

10.1115/1.2911233 ◽

1991 ◽

Vol 113 (4) ◽

pp. 995-1002 ◽

Cited By ~ 24

Author(s):

Y. Cao ◽

A. Faghri

Keyword(s):

Heat Pipe ◽

Three Dimensional ◽

Leading Edge ◽

Heat Pipes ◽

High Heat ◽

Heat Fluxes ◽

Multidimensional Analysis ◽

Vapor Flow ◽

Operating Limits ◽

Good Agreement

A numerical analysis of transient heat pipe performance including nonconventional heat pipes with nonuniform heat distributions is presented. A body-fitted grid system was applied to a three-dimensional wall and wick model, which was coupled with a transient compressible quasi-one-dimensional vapor flow model. The numerical results were first compared with experimental data from cylindrical heat pipes with good agreement. Numerical calculations were then made for a leading edge heat pipe with localized high heat fluxes. Performance characteristics different from conventional heat pipes are illustrated and some operating limits concerning heat pipe design are discussed.

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Numerical Model for the Unsteady Flow Behaviour Inside a Double Suction Pump

Volume 1: Fora, Parts A, B, C, and D ◽

10.1115/fedsm2003-45396 ◽

2003 ◽

Cited By ~ 3

Author(s):

Jose´ Gonza´lez ◽

Carlos Santolaria ◽

Francisco Castro ◽

M. Teresa Parra

Keyword(s):

Numerical Model ◽

Flow Field ◽

Flow Rate ◽

Reference Frames ◽

Three Dimensional ◽

Numerical Procedure ◽

Field Analysis ◽

Dynamic Interactions ◽

Suction Pump ◽

Unsteady Effects

The fluid flow inside a single stage double aspirating pump has been studied using a three-dimensional unsteady numerical model. The main goal is the validation of the numerical procedure proposed and the flow-field analysis at the whole stage. The URANS equations have been solved using a sliding mesh unsteady model, which is able to model the real movement of the impeller inside the volute. The equations have been considered both in the rotating frame for the impeller and in the absolute reference frames, for the inlet and volute sections. Therefore, unsteady effects and dynamic interactions are captured. Mesh independency studies have been carried out and the usual turbomachinery boundary conditions have been imposed. Once the model was validated through performance curve comparison, the flow patterns in the impeller, volute and suction regions have been investigated. Particularly, the suction flow field is of special interest due to induced distortion of the axial and circumferential velocity fields. Besides that, the pressure evolution is also considered in order to study the different patterns at the inlet of the pump, where cavitation is likely to arise. The flow at the suction of this pump is characterized by the existence of a particular geometry that tries to force a uniform flow for nominal flow rate. However, this geometrical configuration produces a strong distortion for off-design conditions. This lack of uniformity produces an unsteady incidence that gives rise to strong loading variations. The study of the evolution of such unsteadiness of the inlet flow throughout the impeller and the volute was also carried out. Even at nominal flow rate, some non uniformities are detected in the pressure distribution at the inlet, that may be caused by the geometrical arrangement of this part of the inlet casing. Instantaneous and averaged pressure fields are studied.

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A Unified Solution Method for the Flow Calculations Along S1 and S2 Stream Surfaces Used for the Computer-Aided Design of Centrifugal Compressor

Volume 1: Turbomachinery ◽

10.1115/88-gt-237 ◽

1988 ◽

Author(s):

Wang Qinghuan ◽

Yu Haoyu

Keyword(s):

Centrifugal Compressor ◽

Computer Aided Design ◽

Solution Method ◽

Three Dimensional ◽

Curvilinear Coordinates ◽

Direct Solution ◽

Aerodynamic Design ◽

Problem Method ◽

Computer Aided ◽

Aided Design

In order to facilitate the aerodynamic design for the computer-aided design (CAD) of centrifugal compressor, a unified direct problem method for the flow calculations along S1 and S2 stream surfaces has been presented in the present paper. A single stream function equation expressed by nonorthogonal curvilinear coordinates and the unified matrix direct solution for the governing equation have been used. This method greatly simplifed the quasi-three dimensional and full dimensional computing program, meanwhile it improved the computing accuracy and the convergence rate. Numerical examples have illustrated the advantages of the new technique for CAD of centrifugal compressors.

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