scholarly journals Numerical Simulations of the Flame of a Single Coaxial Injector

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Victor P. Zhukov ◽  
Markus Feil
Keyword(s):  
Burning Velocity ◽  
Three Dimensional ◽  
Velocity Model ◽  
Test Case ◽  
Test Cases ◽  
Ansys Cfx ◽  
Sst Model ◽  
Planar Laser ◽  
Shear Coaxial Injector ◽  
Coaxial Injector

The processes of mixing and combustion in the jet of a shear-coaxial injector are investigated. Two test cases (nonreacting and reacting) are simulated using the commercial computational fluid dynamics code ANSYS CFX. The first test case is an experiment on the mixing in a nonreacting coaxial jet carried out with the use of planar laser induced fluorescence (PLIF). The second test case is an experiment on the visualization of hydrogen-oxygen flame using PLIF of OH in a single injector combustion chamber at pressure of 53 bar. In the first test case, the two-dimensional axisymmetric simulations are performed using the shear-stress turbulence (SST) model. Due to the dominant flow unsteadiness in the second test case, the turbulence is modeled using transient SAS (Scale-Adaptive Simulation) model. The combustion is modeled using the burning velocity model (BVM) while both two- and three-dimensional simulations are carried out. The numerical model agrees with the experimental data very well in the first test case and adequately in the second test case.

Suite for Smooth Particle Hydrodynamic Code Relevant to Spherical Plasma Liner Formation and Implosion

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Kevin Schillo ◽  
Jason Cassibry ◽  
Mitchell Rodriguez ◽  
Seth Thompson
Keyword(s):  
Three Dimensional ◽  
Smooth Particle Hydrodynamic ◽  
Momentum Conservation ◽  
Plasma Jets ◽  
Test Case ◽  
Test Cases ◽  
Stage Of Development ◽  
Plasma Liner ◽  
L2 Norm ◽  
Hydrodynamic Code

Three-dimensional (3D) modeling of magneto-inertial fusion (MIF) is at a nascent stage of development. A suite of test cases relevant to plasma liner formation and implosion is presented to present the community with some exact solutions for verification of hydrocodes pertaining to MIF confinement concepts. MIF is of particular interest to fusion research, as it may lead to the development of smaller and more economical reactor designs for power and propulsion. The authors present simulated test cases using a new smoothed particle hydrodynamic (SPH) code called SPFMax. These test cases consist of a total of six problems with analytical solutions that incorporate the physics of radiation cooling, heat transfer, oblique-shock capturing, angular-momentum conservation, and viscosity effects. These physics are pertinent to plasma liner formation and implosion by merging of a spherical array of plasma jets as a candidate standoff driver for MIF. An L2 norm analysis was conducted for each test case. Each test case was found to converge to the analytical solution with increasing resolution, and the convergence rate was on the order of what has been reported by other SPH studies.

Influence of Rotation on Dynamic Stall

2013 ◽  
Vol 58 (3) ◽  
pp. 1-9 ◽  
Author(s):  
A. D. Gardner ◽  
K. Richter
Keyword(s):  
Three Dimensional ◽  
Time History ◽  
Turbulence Models ◽  
Dynamic Stall ◽  
Test Case ◽  
Test Cases ◽  
Pitching Moment ◽  
Pitching Motion ◽  
Rotating Blade ◽  
Wind Tunnel Data

A computational investigation of the effect of rotation on two-dimensional (2D) deep dynamic stall has been undertaken, showing that the effect of rotation is to reduce the severity of the pitching moment peak and cause earlier reattachment of the flow. A generic single blade rotor geometry was investigated, which had a pitching oscillation around the quarter-chord axis while in hover, causing angle-driven dynamic stall. The results at the midpoint of the blade have the same Mach number (0.31), Reynolds number (1.15 × 106), and pitching motion (α = 13° ± 7°) as a dynamic stall test case for which significant experimental wind tunnel data and 2D computations exist. The rotating blade is compared with 2D computations and computations using the same blade without rotation at Mach 0.31 and with the same pitching motion. All test cases involve geometries propagating into undisturbed flow with no downwash. The three-dimensional (3D) grid computed without rotation had lower lift at the reference section than for a 2D computation with the same geometric angle of attack time history, and the lift overshoot classically observed for Spalart–Allmaras turbulence models during 2D dynamic stall was significantly reduced in the 3D case. Rotation reduced the strength of the dynamic stall vortex, which reduced the accompanying pitching moment peak by 25%.

scholarly journals Performance Investigation of a Turbocharger Compressor

2012 ◽  
Author(s):  
A. L. de Wet ◽  
T. W. von Backström ◽  
S. J. van der Spuy
Keyword(s):  
Pressure Ratio ◽  
Three Dimensional ◽  
Rotating Stall ◽  
Test Case ◽  
Test Cases ◽  
Vaned Diffuser ◽  
One Dimensional ◽  
Verification Process ◽  
The One ◽  
Modelling Methods

The compressor section of a diesel locomotive turbocharger was re-designed to increase its maximum total-to-total pressure ratio and efficiency. Tests conducted on the prototype compressor showed possible rotating stall in the diffuser section before the designed higher pressure ratio could be achieved. It was decided to simulate the prototype compressor’s operation by using one-dimensional theory [1], followed by a three-dimensional CFD analysis of the compressor. This publication focuses on implementation of the impeller, vaneless annular passage and vaned diffuser one-dimensional theories. A verification process was followed to show the accuracy of the one- and three-dimensional modelling methods using two well-known centrifugal compressor test cases found in the literature [2–5]. Comparing the test case modelling results to available experimental results indicated sufficient accuracy to investigate the prototype compressor’s impeller and diffuser. Conclusions drawn on the prototype compressor’s performance using the one- and three-dimensional modelling methods led to a recommendation to redesign the impeller and diffuser of the prototype compressor.

Application of a Viscous Through-Flow Model to a Modern Axial Low-Pressure Compressor

2021 ◽  
Author(s):  
Arnaud Budo ◽  
Vincent E. Terrapon ◽  
Maarten Arnst ◽  
Koen Hillewaert ◽  
Sophie Mouriaux ◽  
...  
Keyword(s):  
Flow Model ◽  
Three Dimensional ◽  
Test Case ◽  
Test Cases ◽  
Compressor Stage ◽  
Flow Solver ◽  
Closure Models ◽  
Through Flow ◽  
Time Marching ◽  
Pressure Compressor

Abstract This paper describes the evaluation of a newly developed viscous time-marching through-flow solver to two test cases to assess the applicability of the method using correlations from the literature to modern blade designs. The test cases are the classic axial compressor stage CME2 and a modern highly loaded multi-stage axial low-pressure compressor developed by Safran Aero Boosters. The through-flow solver is based on the Navier-Stokes equations and uses a pseudo-time marching method. The closure models currently include terms of major importance: the blade forces and the Reynolds stress. The results are compared to higher-fidelity results including three-dimensional RANS simulations to assess their reliability for design and off-design conditions. The main originality of this work is the evaluation of the CFD-based method in the context of a compressor with highly three-dimensional blades, as such an analysis is not commonly found in the literature. The solver gives realistic predictions of loss and deviation for the compressor stage CME2 at both design and off-design operating conditions. Regarding the second test case, the through-flow simulations based on theoretically non-adapted correlations for such a compressor are still in good agreement with RANS simulations, although the results for the 2nd test case are probably not as good as for the first. These results are a promising first step towards the use of this through-flow model for industrial design. Regarding the ongoing closure models development, suggestions to extend the loss models to a larger range of designs are discussed.

A Multi Blade-Row Linearised Analysis Method for Flutter and Forced Response Predictions in Turbomachinery

2006 ◽  
Author(s):  
Gabriel Saiz ◽  
Mehmet Imregun ◽  
Abdulnaser I. Sayma
Keyword(s):  
Travelling Waves ◽  
Three Dimensional ◽  
Forced Response ◽  
Navier Stokes ◽  
Test Case ◽  
Test Cases ◽  
Simple Test ◽  
Analysis Method ◽  
Turbine Stage ◽  
Blade Row

A three-dimensional time-linearised unsteady Navier-Stokes solver is presented for the computation of multistage unsteady flow in turbomachinery. The objective is to address multistage aeroelastic effects for both flutter and forced response. Since the method is currently being developed, only forced response applications are studied in this paper. With this approach, travelling waves, known as spinning modes, are propagated across the multistage domain in order to take into account the interaction between the blade-rows. The method is first validated over two simple test cases for which analytical solutions were available. It is then tested on a turbine stage test case and multistage effects are evaluated from the contribution of one spinning mode included in the model. The results are compared with both time-linearised single-row and nonlinear multirow methods. Multi-row effects are shown not to be important in this case. However, the test case serves as a validation for the implementation of the methodology and further work will focus on the implementation of several spinning modes and the computations of forced response and flutter cases with several blade-rows.

scholarly journals Numerical Study on Combustion and Atomization Characteristics of Coaxial Injectors for LOX/Methane Engine

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Jiabao Xu ◽  
Ping Jin ◽  
Ruizhi Li ◽  
Jue Wang ◽  
Guobiao Cai
Keyword(s):  
Weber Number ◽  
Numerical Study ◽  
Three Dimensional ◽  
Combustion Stability ◽  
Momentum Ratio ◽  
Shear Coaxial Injector ◽  
Atomization Performance ◽  
Lox Methane ◽  
Coaxial Injector ◽  
Fluid Parameters

The LOX/methane engine has an admirable performance under a supercritical state. However, the properties of methane change drastically with varying injection temperature. Because the injector can greatly affect the atomization and combustion, this study performed a three-dimensional numerical simulation of atomization, combustion, and heat transfer in a subscale LOX/methane engine to evaluate the effect of the main fluid parameters with different methane injection temperatures and different injectors on atomization performance and combustion performance. The results show that the larger propellant momentum ratio and Weber number can improve the heat flux and combustion stability in shear coaxial injector, while the influence in swirl coaxial injector is relatively small. Moreover, in shear coaxial injector and in swirl coaxial injector, the larger propellant momentum ratio and Weber number can reduce the droplet size, enhance atomization performance, and improve the combustion efficiency. The numerical model provides an economical method to evaluate the main fluid parameters and proposes new design principles of injectors in LOX/methane engine.

Model Validation of an Euler-Based 2D-Throughflow Approach for Multistage Axial Turbine Analysis

2020 ◽  
Author(s):  
Sebastian Föllner ◽  
Volker Amedick ◽  
Bernhard Bonhoff ◽  
Dieter Brillert ◽  
Friedrich-Karl Benra
Keyword(s):  
Analytical Solutions ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Meridional Plane ◽  
Test Case ◽  
Test Cases ◽  
Flow Solver ◽  
Axial Turbines ◽  
Development And Validation ◽  
Good Agreement

Abstract In this paper the development and validation of a new meridional throughflow solver for the analysis of multistage axial turbines is presented. The quasi-three-dimensional finite-volume solver named tFlow is based on the inviscid Euler equations. To treat transonic flows with shocks the approximate Riemann solver of Roe for the computation of the inviscid fluxes in combination with the MUSCL approach are used. In the meridional plane turbine blades are numerically modeled by introducing two volume source terms for blade blockage and blade deviation effects. In this contribution four different validation test-cases are discussed. The general fluid solver is validated by analytical solutions of the established Ringleb flow and the simulation of a two-dimensional transonic nozzle flow. In contrast to prior publications [1–3] tFlow uses a different formulation of the blockage effect which is tested using the blockage data of a general convergent-divergent nozzle. Blade deviation effects are validated by comparison with three-dimensional results obtained from the commercial flow solver CFX. The results of tFlow are consistent with the analytical solutions and in case of the blade deviation test-case in good agreement to the three-dimensional results. Compared to fully three-dimensional simulations the developed solver enables faster analyses of multistage axial turbines to evaluate the performance characteristic.

Coupling of the 3D Neutron Kinetic Core Model DYN3D With the CFD Software ANSYS CFX

2014 ◽  
Author(s):  
Alexander Grahn ◽  
Sören Kliem ◽  
Ulrich Rohde
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Reactor Core ◽  
General Purpose ◽  
Core Region ◽  
Core Model ◽  
Hydraulic Calculation ◽  
Test Case ◽  
Control Rod ◽  
Ansys Cfx

This article presents the implementation of a coupling between the 3D neutron kinetic core model DYN3D and the commercial, general purpose computational fluid dynamics (CFD) software ANSYS-CFX. In the coupling approach, parts of the thermal hydraulic calculation are transferred to CFX for its better ability to simulate the three-dimensional coolant redistribution in the reactor core region. The calculation of the heat transfer from the fuel into the coolant remains with DYN3D, which incorporates well tested and validated heat transfer models for rod-type fuel elements. On the CFX side, the core region is modelled based on the porous body approach. The implementation of the code coupling is verified by comparing test case results with reference solutions of the DYN3D standalone version. Test cases cover mini and full core geometries, control rod movement and partial overcooling transients.

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