Roe scheme in generalized coordinates. II - Application to inviscid and viscous flows

Kermani, M.J.; Plett, E. G.

doi:10.2514/6.2001-87

Cited by 12 publications

(8 citation statements)

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“…The governing equations for two dimensional, unsteady, inviscid and compressible flows are composed of the conservation laws of continuity, momentum and energy that are shown in general co-ordinates and fully-conservative form. In the absence of body forces one can write (20,21) :…”

Section: Governing Equationsmentioning

confidence: 99%

High resolution computation of compressible condensing/evaporating moist-air flow for external and internal flows

Hamidi

Kermani

2013

Aeronaut. j. (1968)

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In this paper computation of high resolution, compressible condensing/evaporating moist-air flow for a series of two-dimensional internal and external flows is performed. It has been observed that the inflow wetness content can change the aerothermodynamics of the flow field, e.g. the shock angles. In the case of flow expansion through nozzles, it has also been observed that the content of wetness at nozzles exit in the case of moist-air is more than five times higher than that of pure steam under similar operating conditions. The reason is due to the internal flow of heat from steam portion toward air that accelerates the steam condensation rate. The solver is spatially third-and temporally second-order accurate. Validations of the numerical code are performed versus the experimental data of Moore et al (1973) in the case of very large humidity ratio, ω→∞ (pure steam). Also in the case of low humidity ratio, ω→0 (dry air), the exact solution of shock tube and wedge cases are used to validate our numerical results.

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Section: Governing Equationsmentioning

confidence: 99%

High resolution computation of compressible condensing/evaporating moist-air flow for external and internal flows

Hamidi

Kermani

2013

Aeronaut. j. (1968)

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“…Time integration is done using forward one-step explicit Euler scheme and also the local time stepping technique. To prevent numerical oscillations due to high resolution computations, the van Albada flux limiter [19] is used in the Roe scheme [20,21]. The effect of turbulence on the flow field is applied using Baldwin-Lomax [13] and Shear Stress Transport (SST) [22] turbulence models.…”

Section: Governing Equationsmentioning

confidence: 99%

Development of a Numerical Based Correlation for Performance Losses due to Surface Roughness in Axial Turbines

et al. 2014

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In the present work, a recently developed in-house 2D CFD code is used to study the effect of gas turbine stator blade roughness on various performance parameters of a two-dimensional blade cascade. The 2D CFD model is based on a high resolution flux difference splitting scheme of Roe (1981). The Reynolds Averaged Navier-Stokes (RANS) equations are closed using the zero-equation turbulence model of Baldwin-Lomax (1978) and two-equation Shear Stress Transport (SST) turbulence model. For the smooth blade, results are compared with experimental data to validate the model. Finally, a correlation between roughness Reynolds number and loss coefficient for both turbulence models is presented and tested for three other roughness heights. The results of 2D turbine blade cascades can be used for one-dimensional models such as mean line analysis or quasi-three-dimensional models e.g. streamline curvature method.

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“…iso-£ lines. The cosine direction of the unit vector T\ (which is taken along V£) could be determined as follows: -=;-= cos 0 i + sin 0 j, (5) where 6 is the angle between the vector V£ and xaxis, V£ = U + £yj 9 and |V£| concludes:…”

Section: Metrics Of Transformationmentioning

confidence: 99%

“…In the current study, the van Albada flux limiter, [9], is used to damp the numerical oscillations. For more detail, the reader is referred to [3,5].…”

Section: Right Hand Side Of Eqn 47mentioning

confidence: 99%

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Roe scheme in generalized coordinates. I - Formulations

Kermani

Plett

2001

39th Aerospace Sciences Meeting and Exhibit

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1 Most of the computations by Roe scheme (1981) to solve the fluid equations is performed in the physical domain either over unstructured grids, like some triangular grids, or structured grids, like some quadrilateral grids, say for two-dimensional computations. With the choice of triangular grids some benefits of the Roe scheme, as a non-diffusive scheme in essence, is partially lost due to the grid line obliqueness w.r.t. flow. In contrast, quadrilateral grids are more appropriate for the Roe scheme as they are better able to align with the flow. Besides, with the choice of quadrilateral grids it is also possible to convert the fluid equations from physical to computational domain. There are only very few reports and articles on the application of the Roe scheme in generalized coordinates. To solve the fluid equations by Roe scheme in computational domain (or generalized coordinates) and to give a formula for the numerical flux Roe in generalized coordinates is the main goal of this paper. In detail, the following subjects are addressed in this paper. (1) A comprehensive knowledge of the grid-geometry is obtained. That is, the cosine direction of the grid lines, the cosine direction of the control volume faces and the area of the control volume faces are described in terms of the metrics of transformation from the physical domain to that of the computational domain. (2) The governing equations of fluid motion in physical domain and those in computational domain are put side by side term by term and a formula is obtained to give the numerical flux Roe in generalized coordinates. This numerical flux is written in terms of grid-geometry (metrics of transformation from the physical domain to the computational domain) and flow parameter. In part II of this publication the method is applied to some determining inviscid and viscous cases.

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Roe scheme in generalized coordinates. II - Application to inviscid and viscous flows

Cited by 12 publications

References 13 publications

High resolution computation of compressible condensing/evaporating moist-air flow for external and internal flows

High resolution computation of compressible condensing/evaporating moist-air flow for external and internal flows

Development of a Numerical Based Correlation for Performance Losses due to Surface Roughness in Axial Turbines

Roe scheme in generalized coordinates. I - Formulations

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