Numerical simulation of high speed reacting shear layers using AUSM+- up scheme-based unstructured finite volume method solver

2017 ◽  
Vol 08 (03) ◽  
pp. 1750020 ◽  
Author(s):  
M. Deepu ◽  
M. P. Dhrishit ◽  
S. Shyji
Keyword(s):  
Finite Volume ◽  
High Speed ◽  
Splitting Method ◽  
Time Integration ◽  
Chemical Species ◽  
Shear Layers ◽  
Supersonic Stream ◽  
Reacting Flow ◽  
Two Dimensional ◽  
Flow Solver

Development of an Advection Upstream Splitting Method (AUSM[Formula: see text]-up) scheme-based Unstructured Finite Volume (UFVM) solver for the simulation of two-dimensional axisymmetric/planar high speed compressible turbulent reacting shear layers is presented. The inviscid numerical flux is evaluated using AUSM[Formula: see text]-up upwind scheme. An eight-step hydrogen–oxygen finite rate chemistry model is used to model the development of chemical species in a supersonic reacting flow field. The chemical species terms are alone solved implicitly in this explicit flow solver by rescaling the equation in time. The turbulence modeling has been done using RNG-based [Formula: see text]–[Formula: see text] model. Three-stage Runge–Kutta method has been used for explicit time integration. The nonreacting two-dimensional Cartesian version of the same solver has been successfully validated against experimental and numerical results reported for the wall static pressure data in sonic slot injection to supersonic stream. Detailed validation studies for reacting flow solver has been done using experimental results reported for a coaxial supersonic combustor, in which species profile at various axial locations has been compared. Present numerical solver is useful in simulating combustors of high speed air-breathing propulsion devices.

A Spectrally Accurate 2-D Axisymmetric Photon Monte-Carlo RTE Solver for Hypersonic Entry Flows

2009 ◽  
Author(s):  
Andrew Feldick ◽  
Josh Giegel ◽  
Michael F. Modest
Keyword(s):  
Monte Carlo ◽  
Radiative Transfer ◽  
Ray Tracing ◽  
Hypersonic Flow ◽  
Finite Volume ◽  
Spectral Properties ◽  
Computational Time ◽  
Two Dimensional ◽  
Flow Solver

A two-dimensional axisymmetric ray tracing photon Monte Carlo radiative transfer solver is developed. Like all ray tracing Monte Carlo codes, the ray tracing is performed in 3-D, however, arrangements are made to take advantage of the 2-D nature of the problem, to minimize computational time. The solver is designed to be integrated into finite volume hypersonic flow solvers, and is able to resolve the complex spectral properties of such flows to line-by-line accuracy. The solver is then directly integrated into DPLR, a hypersonic flow solver, and closely coupled calculations are performed.

VALIDATION OF 2D MULTI-BLOCK HIGH-SPEED COMPRESSIBLE TURBULENT FLOW SOLVER

2007 ◽  
Vol 04 (01) ◽  
pp. 33-57 ◽  
Author(s):  
JAWAD KHAWAR ◽  
ANWAR UL-HAQUE ◽  
SAJID RAZA CHAUDHRY
Keyword(s):  
Shock Wave ◽  
Turbulent Flow ◽  
Turbulence Model ◽  
High Speed ◽  
Time Integration ◽  
Flow Simulation ◽  
Stress Model ◽  
Basic Algorithm ◽  
Flow Solver ◽  
Compressible Turbulent Flow

A 2D multi-block high-speed compressible turbulent flow solver CFD2D based on the Jones and Launders two-equation k –ε turbulence model is developed. Method of solution employed is Finite Volume Method. Its basic algorithm is based on the approximate Riemann solver with the three-step Runge–Kutta time integration. Its additional feature includes Wilcox model for compressibility correction of k–ε turbulence model, Girmaji algebraic Reynolds stress (non-linear stress) model and linear stress model for evaluation of turbulent stresses. For validation purpose, code is applied to a 2D diamond aerofoil and a wedge ramp attached to a flat plate. CFD-predicted results are compared to the experimental results for shock wave and shock wave boundary layer interaction on the trailing edge of the fin. Contour plots are also compared to the Schlieren photographs. Flow simulation shows ability of the code to capture the physics of the flow both qualitatively and quantitatively.

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

2020 ◽  
Vol 13 ◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Two Dimensional ◽  
Load Spectrum ◽  
One Dimensional ◽  
Life Estimation ◽  
Load Spectra ◽  
Fatigue Life Estimation ◽  
Program Load Spectrum ◽  
Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

scholarly journals A Fully Implicit Finite Volume Scheme for a Seawater Intrusion Problem in Coastal Aquifers

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1639
Author(s):  
Abdelkrim Aharmouch ◽  
Brahim Amaziane ◽  
Mustapha El Ossmani ◽  
Khadija Talali
Keyword(s):  
Finite Volume ◽  
Coastal Aquifers ◽  
Nonlinear Partial Differential Equations ◽  
Time Integration ◽  
Mass Conservation ◽  
Coupled System ◽  
Finite Volume Scheme ◽  
Time Step ◽  
Volume Scheme ◽  
Fully Implicit

We present a numerical framework for efficiently simulating seawater flow in coastal aquifers using a finite volume method. The mathematical model consists of coupled and nonlinear partial differential equations. Difficulties arise from the nonlinear structure of the system and the complexity of natural fields, which results in complex aquifer geometries and heterogeneity in the hydraulic parameters. When numerically solving such a model, due to the mentioned feature, attempts to explicitly perform the time integration result in an excessively restricted stability condition on time step. An implicit method, which calculates the flow dynamics at each time step, is needed to overcome the stability problem of the time integration and mass conservation. A fully implicit finite volume scheme is developed to discretize the coupled system that allows the use of much longer time steps than explicit schemes. We have developed and implemented this scheme in a new module in the context of the open source platform DuMu X . The accuracy and effectiveness of this new module are demonstrated through numerical investigation for simulating the displacement of the sharp interface between saltwater and freshwater in groundwater flow. Lastly, numerical results of a realistic test case are presented to prove the efficiency and the performance of the method.

Accelerating laser processes with a smart two-dimensional polygon mirror scanner for ultra-fast beam deflection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Roessler ◽  
André Streek
Keyword(s):  
Energy Distribution ◽  
Real Time ◽  
Laser Processing ◽  
High Speed ◽  
Beam Deflection ◽  
Two Dimensional ◽  
Heat Accumulation ◽  
Field Programmable ◽  
Drill Holes ◽  
Average Laser

Abstract In laser processing, the possible throughput is directly scaling with the available average laser power. To avoid unwanted thermal damage due to high pulse energy or heat accumulation during MHz-repetition rates, energy distribution over the workpiece is required. Polygon mirror scanners enable high deflection speeds and thus, a proper energy distribution within a short processing time. The requirements of laser micro processing with up to 10 kW average laser powers and high scan speeds up to 1000 m/s result in a 30 mm aperture two-dimensional polygon mirror scanner with a patented low-distortion mirror configuration. In combination with a field programmable gate array-based real-time logic, position-true high-accuracy laser switching is enabled for 2D, 2.5D, or 3D laser processing capable to drill holes in multi-pass ablation or engraving. A special developed real-time shifter module within the high-speed logic allows, in combination with external axis, the material processing on the fly and hence, processing of workpieces much larger than the scan field.

scholarly journals Integrating Semilinear Wave Problems with Time-Dependent Boundary Values Using Arbitrarily High-Order Splitting Methods

Mathematics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1113
Author(s):  
Isaías Alonso-Mallo ◽  
Ana M. Portillo
Keyword(s):  
Numerical Experiments ◽  
Splitting Method ◽  
Method Of Lines ◽  
Time Integration ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
High Order ◽  
Time Dependent ◽  
Boundary Values ◽  
Lipschitz Continuous

The initial boundary-value problem associated to a semilinear wave equation with time-dependent boundary values was approximated by using the method of lines. Time integration is achieved by means of an explicit time method obtained from an arbitrarily high-order splitting scheme. We propose a technique to incorporate the boundary values that is more accurate than the one obtained in the standard way, which is clearly seen in the numerical experiments. We prove the consistency and convergence, with the same order of the splitting method, of the full discretization carried out with this technique. Although we performed mathematical analysis under the hypothesis that the source term was Lipschitz-continuous, numerical experiments show that this technique works in more general cases.

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