Numerical investigation of transverse sonic injection in a non-reacting supersonic combustor

2005 ◽  
Vol 219 (3) ◽  
pp. 205-215 ◽  
Author(s):  
P Manna ◽  
D Chakraborty
Keyword(s):  
Turbulence Model ◽  
Stokes Equations ◽  
Near Field ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Supersonic Stream ◽  
Scramjet Combustor ◽  
The Difference ◽  
Experimental Values ◽  
Sonic Injection

Efficient combustion and heat release in scramjet flows depend on effective mixing of the fuel in supersonic streams. Usually, transverse sonic injection in-stages are employed as one of the suitable means for efficient supersonic combustor design. Numerical simulations are carried out to study the mixing characteristics of staged sonic air injections in supersonic stream ( M = 2.07) behind a backward-facing step in scramjet combustor by solving three-dimensional Navier-Stokes equations along with K-ε turbulence model with a commercial CFD software CFX-TASCFlow. Computed results of the jet penetration and spreading show very good agreement with the experimental values and the results of other computations. A good overall match has been obtained between the experimental values and the computation for various flow profiles at various axial locations in the combustor. However, the values differ in the near-field region at the injection plane. The assumed uniformity of the flow-field properties at the injection orifice and/or the inadequacy of the turbulence model considered in this study is conjectured to be the cause of the difference.

scholarly journals Numerical Study on the Solid Fuel Rocket Scramjet Combustor with Cavity

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1235 ◽  
Author(s):  
Chaolong Li ◽  
Zhixun Xia ◽  
Likun Ma ◽  
Xiang Zhao ◽  
Binbin Chen
Keyword(s):  
Solid Fuel ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Combustion Efficiency ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Particle Combustion ◽  
Scramjet Combustor ◽  
Cavity Configuration

Scramjet based on solid propellant is a good supplement for the power device of future hypersonic vehicles. A new scramjet combustor configuration using solid fuel, namely, the solid fuel rocket scramjet (SFRSCRJ) combustor is proposed. The numerical study was conducted to simulate a flight environment of Mach 6 at a 25 km altitude. Three-dimensional Reynolds-averaged Navier–Stokes equations coupled with shear stress transport (SST) k − ω turbulence model are used to analyze the effects of the cavity and its position on the combustor. The feasibility of the SFRSCRJ combustor with cavity is demonstrated based on the validation of the numerical method. Results show that the scramjet combustor configuration with a backward-facing step can resist high pressure generated by the combustion in the supersonic combustor. The total combustion efficiency of the SFRSCRJ combustor mainly depends on the combustion of particles in the fuel-rich gas. A proper combustion organization can promote particle combustion and improve the total combustion efficiency. Among the four configurations considered, the combustion efficiency of the mid-cavity configuration is the highest, up to about 70%. Therefore, the cavity can effectively increase the combustion efficiency of the SFRSCRJ combustor.

scholarly journals Three-Dimensional Turbulent Vortex Shedding From a Surface-Mounted Square Cylinder: Predictions With Large-Eddy Simulations and URANS

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
B. A. Younis ◽  
A. Abrishamchi
Keyword(s):  
Experimental Data ◽  
Turbulence Model ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Reynolds Stresses ◽  
Mean Flow ◽  
Navier Stokes Equations ◽  
Large Eddy

The paper reports on the prediction of the turbulent flow field around a three-dimensional, surface mounted, square-sectioned cylinder at Reynolds numbers in the range 104–105. The effects of turbulence are accounted for in two different ways: by performing large-eddy simulations (LES) with a Smagorinsky model for the subgrid-scale motions and by solving the unsteady form of the Reynolds-averaged Navier–Stokes equations (URANS) together with a turbulence model to determine the resulting Reynolds stresses. The turbulence model used is a two-equation, eddy-viscosity closure that incorporates a term designed to account for the interactions between the organized mean-flow periodicity and the random turbulent motions. Comparisons with experimental data show that the two approaches yield results that are generally comparable and in good accord with the experimental data. The main conclusion of this work is that the URANS approach, which is considerably less demanding in terms of computer resources than LES, can reliably be used for the prediction of unsteady separated flows provided that the effects of organized mean-flow unsteadiness on the turbulence are properly accounted for in the turbulence model.

A Reynolds-Averaged Navier-Stokes Solver in a Turbomachinery Design System

2007 ◽  
Author(s):  
Fahua Gu ◽  
Mark R. Anderson
Keyword(s):  
Turbulence Model ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Integrated Design ◽  
Navier Stokes ◽  
Design System ◽  
Navier Stokes Equations ◽  
Wall Functions ◽  
Machine Performance ◽  
Reynolds Averaged Navier Stokes

The design of turbomachinery has been focusing on the improvement of the machine efficiency and the reduction of the design cost. This paper presents an integrated design system to create the machine geometry and to predict the machine performance at different levels of approximation, including one-dimensional design and analysis, quasi-three-dimensional-(blade-to-blade, throughflow) and full-three-dimensional-steady-state CFD analysis. One of the most important components, the Reynolds-averaged Navier-Stokes solver, is described in detail. It originated from the Dawes solver with numerous enhancements. They include the use of the low speed pre-conditioned full Navier-Stokes equations, the addition of the Spalart-Allmaras turbulence model and an improvement of wall functions related with the turbulence model. The latest upwind scheme, AUSM, has been implemented too. The Dawes code has been rewritten into a multi-block solver for O, C, and H grids. This paper provides some examples to evaluate the effect of grid topology on the machine performance prediction.

Numerical research on the performance of solid fuel rocket scramjet combustor

2021 ◽  
pp. 095441002110372
Author(s):  
Hao Huang ◽  
Zhiwei Feng ◽  
Likun Ma ◽  
Tao Yang ◽  
Chaolong Li
Keyword(s):  
Solid Fuel ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Efficiency ◽  
Navier Stokes ◽  
Height Ratio ◽  
Navier Stokes Equations ◽  
Carbon Particles ◽  
Scramjet Combustor ◽  
Numerical Research

Combustion efficiency is the main factor affecting the performance of solid fuel rocket scramjet. To reveal the influence of combustor configuration on performance and further improve combustion efficiency, the influence of the width-height ratio of the rectangle-section combustor on the performance of solid fuel rocket scramjet is investigated numerically in this article. Three-dimensional compressible Reynolds-averaged Navier-Stokes equations coupled with shear stress transport k– ω turbulence model are employed to simulate the aerodynamics. The Euler–Lagrange approach is used to calculate the multiphase flow. Combustion of carbon particles is modeled by the improved Moving Flame Front model. Accuracy of the present numerical model is validated by the experimental data of a rectangle-section combustor from literature. Results show that as the width-height ratio increases, the combustion efficiency increases first and then decreases. The influence of cavity and its position on the performance are also investigated. Results show that cavity can significantly improve combustion efficiency. The effect of cavity position on performance is related to the distribution of particles.

AERODYNAMIC PERFORMANCE OF AN AXIAL COMPRESSOR WITH A CASING GROOVE COMBINED WITH INJECTION

2013 ◽  
Vol 37 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Dae-Woong Kim ◽  
Jin-Hyuk Kim ◽  
Kwang-Yong Kim
Keyword(s):  
Turbulence Model ◽  
Parametric Study ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Stall Margin ◽  
Transonic Axial Compressor

Aerodynamic performance of a transonic axial compressor with a casing groove combined with injection has been investigated in this work. Three-dimensional Reynolds-averaged Navier–Stokes equations with k-ε turbulence model are discretized by finite volume approximations and solved on hexahedral grids for the flow analyses. For parametric study, the front and rear lengths and height of the casing groove are selected as the geometric parameters and are changed with constant injection to investigate their effects on the stall margin and peak adiabatic efficiency. As a result of the parametric study, the maximum stall margin and peak adiabatic efficiency are found to be obtained in the axial compressor having 70% height of the reference groove. The results show that the application of the casing groove combined with injection to an axial compressor is effective for the simultaneous improvement of both the stall margin and peak adiabatic efficiency of the compressor.

scholarly journals A Study of RANS Turbulence Models in Fully Turbulent Jets: A Perspective for CFD-DEM Simulations

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 271
Author(s):  
Dustin Weaver ◽  
Sanja Mišković
Keyword(s):  
Stokes Equations ◽  
Near Field ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Turbulent Jets ◽  
Navier Stokes ◽  
Straight Tube ◽  
Developed Turbulence ◽  
Similar Work ◽  
Tube Geometry

This paper presents an analysis of linear viscous stress Favre averaged turbulence models for computational fluid dynamics (CFD) of fully turbulent round jets with a long straight tube geometry in the near field. Although similar work has been performed in the past with very relevant solutions, considerations were not given for the issues and limitations involved with coupling between an Eulerian and Lagrangian phase, such as in fully two-way coupled CFD-DEM. These issues include limitations on solution domain, mesh cell size, wall modelling, and momentum coupling between the two phases in relation to the particles size. Therefore, within these considerations, solutions are provided to the Navier–Stokes equations with various turbulence models using a three-dimensional wedge long straight tube geometry for fully developed turbulence flow. Simulations are performed with a Reynolds number of 13,000 and 51,000 using two different tube diameters. It is found that a modified k-ε turbulence model achieved the most agreeable results for both the velocity and turbulent flow fields between these two flow regimes, while a modified k-ω SST/BSL also provided suitable results.

ON NONPARALLEL STABILITY OF THREE-DIMENSIONAL COMPRESSIBLE BOUNDARY LAYERS

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1503-1506
Author(s):  
JIXUE LIU ◽  
DENGBIN TANG ◽  
GUOXING ZHU
Keyword(s):  
Boundary Layers ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Local Method ◽  
Curvature Variation ◽  
Compressible Boundary Layers ◽  
Curvilinear Coordinate ◽  
The Difference

Nonparallel stability of the compressible boundary layers for three-dimensional configurations having large curvature variation on the surface is investigated by using the parabolic stability equations, which are derived from the Navier-Stokes equations in the curvilinear coordinate system. The difference schemes with fourth-order accuracy can be used in the entire computational regions. The global method is combined with the local method using a new iterative formula, thus more precise eigenvalues are obtained, and fast convergences are achieved. Computed curves of the amplification factor and shape functions of disturbances show clearly variable process of the flow stability, and agree well with other available results.

Numerical Investigation of a Model Scramjet Combustor Using DDES

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Junsu Shin ◽  
Hong-Gye Sung
Keyword(s):  
Stokes Equations ◽  
Splitting Method ◽  
Time Integration ◽  
Three Dimensional ◽  
Finite Volume Methods ◽  
Navier Stokes ◽  
Mixing Efficiency ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Scramjet Combustor

AbstractNon-reactive flows moving through a model scramjet were investigated using a delayed detached eddy simulation (DDES), which is a hybrid scheme combining Reynolds averaged Navier-Stokes scheme and a large eddy simulation. The three dimensional Navier-Stokes equations were solved numerically on a structural grid using finite volume methods. An in-house was developed. This code used a monotonic upstream-centered scheme for conservation laws (MUSCL) with an advection upstream splitting method by pressure weight function (AUSMPW+) for space. In addition, a 4th order Runge-Kutta scheme was used with preconditioning for time integration. The geometries and boundary conditions of a scramjet combustor operated by DLR, a German aerospace center, were considered. The profiles of the lower wall pressure and axial velocity obtained from a time-averaged solution were compared with experimental results. Also, the mixing efficiency and total pressure recovery factor were provided in order to inspect the performance of the combustor.

Numerical Simulation of Dual-Mode Scramjet Combustor with Significant Upstream Interaction

2012 ◽  
Vol 2 (3) ◽  
pp. 60-74
Author(s):  
Rahul Ingle ◽  
Debasis Chakraborty
Keyword(s):  
Surface Pressure ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Interaction Model ◽  
Navier Stokes ◽  
Dual Mode ◽  
Fast Kinetics ◽  
Scramjet Combustor ◽  
Flow Features

This paper is concerned with a numerical study corresponding to experimental investigation of Chinzei and co-workers on hydrogen fueled dual-mode scramjet engine essentially to understand the key features of upstream interaction, mixing and combustion. Three dimensional Navier Stokes equations along with a K-? turbulence model and infinitely fast kinetics are solved using commercial CFD software. Reasonable agreement has been obtained between the computed surface pressure with experimental values and the results of other numerical simulations. Insights into the flow features inside the combustor are obtained through analysis of various thermochemical parameters. The comparison of surface pressure with experimental results and other numerical results demonstrated that simple kinetics and turbulence – chemistry interaction model may be adequate to address the overall flow features in the combustor. A principal conclusion is that the boundary layer at the combustor entry has a pronounced effect on the flow development in the dual-mode scramjet combustor and causes significant upstream interaction.

scholarly journals A Study of RANS Turbulence Models in Fully Turbulent Jets: A Perspective for CFD-DEM Simulations

2021 ◽  
Author(s):  
Dustin Steven Weaver ◽  
Sanja Mišković
Keyword(s):  
Stokes Equations ◽  
Near Field ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Turbulent Jets ◽  
Navier Stokes ◽  
Straight Tube ◽  
Developed Turbulence ◽  
Similar Work ◽  
Tube Geometry

This paper presents an analysis of linear viscous stress Favre-Averaged turbulence models for computational fluid dynamics (CFD) of fully turbulent round jets with a long straight tube geometry in the near field. Although similar work has been performed in the past with very relevant solutions, considerations were not given for the issues and limitations involved with coupling between an Eulerian and Lagrangian phase, such as in fully two-way coupled CFD-DEM. These issues include limitations on solution domain, mesh cell size, wall modelling, and momentum coupling between the two phases in relation to the particles size. Therefore, within these considerations, solutions are provided to the Navier-Stokes equations with various turbulence models using a three-dimensional wedge long straight tube geometry for fully developed turbulence flow. Simulations are performed with a Reynolds number of 15000 and 50000 using two different tube diameters. It is found that a modified k−ε turbulence model achieved the most agreeable results for both the velocity and turbulent flow fields between these two flow regimes, while a modified k−ω SST/BSL also provided suitable results.

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