Discussion on “Observation of the Mold-Filling Process of a Large Hydro-turbine Guide Vane Casting”

Gas turbine performance is closely linked to the turbine inlet temperature, which is limited by the turbine guide vanes ability to withstand the massive thermal loads. Thus, steam cooling has been introduced as an advanced cooling technology to improve the efficiency of modern high-temperature gas turbines. This study compares the cooling performance of compressed air and steam in the renowned radially cooled NASA C3X turbine guide vane, using a numerical model. The conjugate heat transfer (CHT) model is based on the RANS-method, where the shear stress transport (SST) k−ω model is selected to predict the effects of turbulence. The numerical model is validated against experimental pressure and temperature distributions at the external surface of the vane. The results are in good agreement with the experimental data, with an average error of 1.39% and 3.78%, respectively. By comparing the two coolants, steam is confirmed as the superior cooling medium. The disparity between the coolants increases along the axial direction of the vane, and the total volume average temperature difference is 30 K. Further investigations are recommended to deal with the local hot-spots located near the leading- and trailing edge of the vane.

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Three-Dimensional Numerical Simulation of Mold Filling Process in Compression Resin Transfer Molding

Applied Composite Materials ◽

10.1007/s10443-014-9402-7 ◽

2014 ◽

Vol 22 (2) ◽

pp. 209-230 ◽

Cited By ~ 4

Author(s):

Bo Yang ◽

Tianguo Jin ◽

Jianguang Li ◽

Fengyang Bi

Keyword(s):

Numerical Simulation ◽

Resin Transfer Molding ◽

Three Dimensional ◽

Mold Filling ◽

Filling Process ◽

Transfer Molding ◽

Compression Resin Transfer Molding

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Application of RANS and LES to the Prediction of Flows in High Pressure Turbine Components

Volume 7: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2011-46518 ◽

2011 ◽

Cited By ~ 2

Author(s):

Nicolas Gourdain ◽

Laurent Y. M. Gicquel ◽

Remy Fransen ◽

Elena Collado ◽

Tony Arts

Keyword(s):

Heat Transfer ◽

Vortex Shedding ◽

Guide Vane ◽

Unsteady Flows ◽

Separated Flow ◽

Heat Fluxes ◽

Boundary Layer Transition ◽

Wall Heat Transfer ◽

Layer Transition ◽

Turbine Guide Vane

This paper investigates the capability of numerical simulations to estimate unsteady flows and wall heat fluxes in turbine components with both structured and unstructured flow solvers. Different numerical approaches are assessed, from steady-state methods based on the Reynolds Averaged Navier-Stokes (RANS) equations to more sophisticated methods such as the Large Eddy Simulation (LES) technique. Three test cases are investigated: the vortex shedding induced by a turbine guide vane, the wall heat transfer in another turbine guide vane and a separated flow phenomenon in an internal turbine cooling channel. Steady flow simulations usually fail to predict the mean effects of unsteady flows (such as vortex shedding) and wall heat transfer, mainly because laminar-to turbulent transition and the inlet turbulent intensity are not correctly taken into account. Actually, only the LES (partially) succeeds to accurately estimate unsteady flows and wall heat fluxes in complex configurations. The results presented in this paper indicate that this method considerably improves the level of physical description (including boundary layer transition). However, the LES still requires developments and validations for such complex flows. This study also points out the dependency of results to parameters such as the freestream turbulence intensity. When feasible solutions obtained with both structured and unstructured flow solvers are compared to experimental data.

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Element modeling of FEM on the pressure field in the powder injection mold filling process

Journal of Materials Processing Technology ◽

10.1016/s0924-0136(02)01070-1 ◽

2003 ◽

Vol 137 (1-3) ◽

pp. 74-77 ◽

Cited By ~ 4

Author(s):

Bing-yan Jiang ◽

Jue Zhong ◽

Bai-yun Huang ◽

Xuan-hui Qu ◽

Yi-min Li

Keyword(s):

Pressure Field ◽

Mold Filling ◽

Powder Injection ◽

Injection Mold ◽

Filling Process ◽

Element Modeling

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Numerical and Experimental Analysis of Secondary Flow in Modern State-of-the-Art Low Pressure Guide Vane Rows

Volume 1: Turbomachinery ◽

10.1115/95-gt-189 ◽

1995 ◽

Cited By ~ 1

Author(s):

Ernst Lindner

Keyword(s):

Aspect Ratio ◽

Secondary Flow ◽

Total Pressure ◽

Guide Vane ◽

Numerical Results ◽

Flow Behaviour ◽

Inlet Guide Vane ◽

Streamwise Vorticity ◽

Pressure Losses ◽

Turbine Guide Vane

To enhance the performance of the inlet guide vane and the annular duct of a jet engine, a detailed investigation of annular cascades with two different types of turbine guide vane rows is made. The first one is a leaned guide vane with an aspect ratio of two and a half and a transition duct ahead of the vane. To avoid the losses associated to the decelerating transition duct an alternative vane is designed and investigated with the same inlet and exit conditions. In this case the chord of the vane is increased to the effect that the vane begins immediately at the enterance of the diverging annulus and so a continuously accelerated flow is achieved. To maintain a good performance for this configuration a bowed-type vane with an aspect ratio of one is designed. The aim of the investigation is to obtain detailed informations on the secondary flow behaviour with particular regard to the development of the total pressure losses and the streamwise vorticity of the vortices inside and behind the blade rows. In the first step a three-dimensional, structured, explicit finite-volume flow-solver with a k–ε turbulence model is validated against the measurements, which were made in cross-sections behind the blades. Having proved that the numerical results are very close to the experimental ones, the secondary flow behaviour inside and behind the blade rows is analysed in the second step. By calculating the streamwise vorticity from the numerical results the formation of horse-shoe vortex, passage-vortex and the trailing edge vortex shed is investigated. The differences of the vortical motion and the formation of the total pressure losses between the two configurations of turbine guide vane rows are discussed.

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