Cooling Considerations for Design of a Radial Inflow Turbine

1977 ◽  
Author(s):  
A. Hamed ◽  
Y. Sheoran ◽  
W. Tabakoff
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Computer Time ◽  
Coolant Temperature ◽  
Internal Cooling ◽  
Present Formulation ◽  
Mechanical Integrity ◽  
Cooling Design ◽  
Time Savings ◽  
Radial Inflow Turbine

A numerical study to determine the temperature distribution in the rotor of a radial inflow turbine is presented. Internal cooling passages are modeled in the present formulation in order to carry out solid and coolant temperature computations simultaneously resulting in a considerable computer time savings. The stresses due to centrifugal and thermal loadings are determined in an actual rotor and the effect of cooling design on its mechanical integrity is discussed.

Adiabatic and Overall Effectiveness for a Fully Cooled Turbine Vane

2013 ◽  
Author(s):  
Thomas E. Dyson ◽  
John W. McClintic ◽  
David G. Bogard ◽  
Sean D. Bradshaw
Keyword(s):  
Biot Number ◽  
Film Cooling ◽  
Large Scale ◽  
Internal Heat ◽  
Coolant Temperature ◽  
Internal Cooling ◽  
Impingement Cooling ◽  
Turbine Vane ◽  
Cooling Design ◽  
Overall Effectiveness

Adiabatic and overall effectiveness data were measured for a fully cooled, scaled up turbine vane model in a low speed linear cascade with a chord-exit Reynolds number of 700,000. The overall effectiveness is a measure of the external surface temperature relative to the mainstream temperature and the inlet coolant temperature, and consequently is a direct measure of how effectively the surface is cooled. This can be determined experimentally when the experimental model is constructed so that the Biot number of the model and the ratio of the external to internal heat transfer coefficient are chosen so that the model has a similar thermal behavior to that of an actual engine component. The model used in this study had a cooling design that consisted of 149 total coolant holes in 13 rows, including a showerhead containing five rows of holes. The model also incorporated an internal impingement cooling configuration. An identical model was also constructed out of low conductivity foam to measure adiabatic effectiveness. This is the first study to use a large scale, matched Biot number model to measure engine representative overall effectiveness for a vane employing full coverage film cooling. The focus of this research was to determine the relative contributions of the external and internal cooling, and to serve as a baseline for validation of computational simulations. Additionally, a simplified model using measurements of overall effectiveness with internal cooling alone was used to predict overall effectiveness downstream of the showerhead.

scholarly journals Numerical study on temperature distribution of tunnel structure in fires

2021 ◽  
Vol 25 ◽  
pp. 100874
Author(s):  
Xin Xu ◽  
Guoqing Zhu ◽  
Xiaojin Zhang ◽  
Guoqiang Chai ◽  
Tianwei Chu
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Tunnel Structure

scholarly journals Thermal Analysis of Cold Plate with Different Configurations for Thermal Management of a Lithium-Ion Battery

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Seyed Saeed Madani ◽  
Erik Schaltz ◽  
Søren Knudsen Kær
Keyword(s):  
Thermal Analysis ◽  
Temperature Distribution ◽  
Lithium Ion Battery ◽  
Thermal Management ◽  
Electric Vehicles ◽  
Heat Dissipation ◽  
Lithium Ion ◽  
Cold Plate ◽  
Liquid Cooling ◽  
Cooling Design

Thermal analysis and thermal management of lithium-ion batteries for utilization in electric vehicles is vital. In order to investigate the thermal behavior of a lithium-ion battery, a liquid cooling design is demonstrated in this research. The influence of cooling direction and conduit distribution on the thermal performance of the lithium-ion battery is analyzed. The outcomes exhibit that the appropriate flow rate for heat dissipation is dependent on different configurations for cold plate. The acceptable heat dissipation condition could be acquired by adding more cooling conduits. Moreover, it was distinguished that satisfactory cooling direction could efficiently enhance the homogeneity of temperature distribution of the lithium-ion battery.

Experimental and Numerical Study on the Effects of the Relative Position of Film Hole and Orientation Ribs on the Film Cooling With Ribbed Cross-Flow Coolant Channel

2020 ◽  
Author(s):  
Bingran Li ◽  
Cunliang Liu ◽  
Lin Ye ◽  
Huiren Zhu ◽  
Fan Zhang
Keyword(s):  
Heat Transfer ◽  
Relative Position ◽  
Film Cooling ◽  
Numerical Study ◽  
Cross Flow ◽  
Internal Cooling ◽  
Transfer Coefficients ◽  
Cooling Performance ◽  
Heat Transfer Coefficients ◽  
Numerical Studies

Abstract To investigate the application of ribbed cross-flow coolant channels with film hole effusion and the effects of the internal cooling configuration on film cooling, experimental and numerical studies are conducted on the effect of the relative position of the film holes and different orientation ribs on the film cooling performance. Three cases of the relative position of the film holes and different orientation ribs (post-rib, centered, and pre-rib) in two ribbed cross-flow channels (135° and 45° orientation ribs) are investigated. The film cooling performances are measured under three blowing ratios by the transient liquid crystal measurement technique. A RANS simulation with the realizable k-ε turbulence model and enhanced wall treatment is performed. The results show that the cooling effectiveness and the downstream heat transfer coefficient for the 135° rib are basically the same in the three position cases, and the differences between the local effectiveness average values for the three are no more than 0.04. The differences between the heat transfer coefficients are no more than 0.1. The “pre-rib” and “centered” cases are studied for the 45° rib, and the position of the structures has little effect on the film cooling performance. In the different position cases, the outlet velocity distribution of the film holes, the jet pattern and the discharge coefficient are consistent with the variation in the cross flow. The related research previously published by the authors showed that the inclination of the ribs with respect to the holes affects the film cooling performance. This study reveals that the relative positions of the ribs and holes have little effect on the film cooling performance. This paper expands and improves the study of the effect of the internal cooling configuration on film cooling and makes a significant contribution to the design and industrial application of the internal cooling channel of a turbine blade.

Influence of Anisotropic Thermal Conductivity on Overall Cooling Effectiveness on a Film Cooled Leading Edge

2021 ◽  
pp. 1-22
Author(s):  
Carol Bryant ◽  
James L. Rutledge
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Film Cooling ◽  
Leading Edge ◽  
Ceramic Matrix Composites ◽  
Internal Cooling ◽  
Matrix Composites ◽  
Edge Region ◽  
Turbine Engine ◽  
Anisotropic Thermal Conductivity

Abstract Increasing interest in the use of ceramic matrix composites (CMCs) for gas turbine engine hot gas path components requires a thorough examination of the thermal behavior one may expect of such components. Their highly anisotropic thermal conductivity is a substantial departure from traditional metallic components and can influence the temperature distribution in surprising ways. With the ultimate surface temperature dependent upon the internal cooling scheme, including cooling from within the film cooling holes themselves, as well as the external film cooling, the relative influence of these contributions to cooling can be affected by the directionality of the thermal conductivity. Conjugate heat transfer computational simulations were performed to evaluate the effect of anisotropy in the leading edge region of a turbine component. The leading edge region is modeled as a fully film-cooled half cylinder with a flat afterbody. The anisotropic directionality of the thermal conductivity is shown to have a significant effect on the temperature distribution over the surface of the leading edge. While structural considerations with CMC components are often paramount, designers should be aware of the thermal ramifications associated with the selection of the CMC layup.

A Parametric Numerical Study of the Effects of Freestream Turbulence Intensity and Length Scale on Anti-Vortex Film Cooling Design at High Blowing Ratio

2013 ◽  
Author(s):  
Timothy W. Repko ◽  
Andrew C. Nix ◽  
James D. Heidmann
Keyword(s):  
Turbulence Intensity ◽  
Film Cooling ◽  
Numerical Study ◽  
Length Scale ◽  
Freestream Turbulence ◽  
Cooling Effectiveness ◽  
Length Scales ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Cooling Design

An advanced, high-effectiveness film-cooling design, the anti-vortex hole (AVH) has been investigated by several research groups and shown to mitigate or counter the vorticity generated by conventional holes and increase film effectiveness at high blowing ratios and low freestream turbulence levels. [1, 2] The effects of increased turbulence on the AVH geometry were previously investigated and presented by researchers at West Virginia University (WVU), in collaboration with NASA, in a preliminary CFD study [3] on the film effectiveness and net heat flux reduction (NHFR) at high blowing ratio and elevated freestream turbulence levels for the adjacent AVH. The current paper presents the results of an extended numerical parametric study, which attempts to separate the effects of turbulence intensity and length-scale on film cooling effectiveness of the AVH. In the extended study, higher freestream turbulence intensity and larger scale cases were investigated with turbulence intensities of 5, 10 and 20% and length scales based on cooling hole diameter of Λx/dm = 1, 3 and 6. Increasing turbulence intensity was shown to increase the centerline, span-averaged and area-averaged adiabatic film cooling effectiveness. Larger turbulent length scales were shown to have little to no effect on the centerline, span-averaged and area-averaged adiabatic film-cooling effectiveness at lower turbulence levels, but slightly increased effect at the highest turbulence levels investigated.

Effect of Wall Conduction on Combined Free and Forced Laminar Convection in Horizontal Rectangular Channels

1987 ◽  
Vol 109 (4) ◽  
pp. 936-942 ◽  
Author(s):  
G. J. Hwang ◽  
F. C. Chou
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Temperature Distribution ◽  
Finite Difference ◽  
Aspect Ratio ◽  
Finite Difference Method ◽  
Numerical Study ◽  
Fully Developed Flow ◽  
Rectangular Channels ◽  
Laminar Convection

This paper presents a numerical study of the effect of peripheral wall conduction on combined free and forced laminar convection in hydrodynamically and thermally fully developed flow in horizontal rectangular channels with uniform heat input axially, In addition to the Prandtl number, the Grashof number Gr+, and the aspect ratio γ, a parameter Kp indicating the significance of wall conduction plays an important role in heat transfer. A finite-difference method utilizing a power-law scheme is employed to solve the system of governing partial differential equations coupled with the equation for wall conduction. The numerical solution covers the parameters: Pr = 7.2 and 0.73, γ = 0.5, 1, and 2, Kp = 10−4–104, and Gr+ = 0–1.37×105. The flow patterns and isotherms, the wall temperature distribution, the friction factor, and the Nusselt number are presented. The results show a significant effect of the conduction parameter Kp.

Numerical Analysis of Fluid Flow in an Internal Turbine Blade Cooling Passage

1995 ◽  
Author(s):  
Marc L. Babich ◽  
Song-Lin Yang ◽  
Donna J. Michalek ◽  
Oner Arici
Keyword(s):  
Turbine Blade ◽  
High Efficiency ◽  
Stokes Equations ◽  
Numerical Study ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Grid Turbulence ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Cooling Passage

The need to develop ultra-high efficiency turbines demands the exploration of methods which will improve the thermal efficiency and the specific thrust of the engine. One means of achieving these goals is to increase the turbine inlet temperature. In order to accomplish this, further advances in turbine blade cooling technology will have to be realized. A technique which has only recently been used in the analysis of turbine blade cooling is computational fluid dynamics. The purpose of this paper is to present a numerical study of the flowfield inside of the internal cooling passage of a radial turbine blade. The passage is modeled as two-dimensional and non-rotating. The flowfield solutions are obtained using a pseudo-compressible formulation of the Navier-Stokes equations. The spatial discretization is performed using a symmetric second-order accurate TVD (Total Variational Diminishing) scheme. Calculations are performed on a multi-block-structured grid. Turbulence is modeled using a modified κ-ω model. In the absence of experimental data, results appear to be realistic based on common experiences with fluid mechanics.

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