scholarly journals Validating the k-ω Turbulence Model for 3D Flows within the CFD Solver Eilmer

2016 ◽  
Vol 846 ◽  
pp. 67-72
Author(s):  
Samuel Stennett ◽  
Wilson Chan ◽  
David E. Gildfind ◽  
Peter Jacobs
Keyword(s):  
Turbulence Model ◽  
High Speed ◽  
Compressible Flows ◽  
Three Dimensional ◽  
Cross Flow ◽  
Main Flow ◽  
Test Cases ◽  
Flow Features ◽  
The University ◽  
3D Flows

The computational fluid dynamics solver Eilmer has proven useful to The University of Queensland’s Centre for Hypersonics for its ability to simulate high-speed compressible flows. In Eilmer, turbulence is modelled using Wilcox’s 2006 k-ω model. While the turbulence model implementation has been validated for two-dimensional and axisymmetric flows, validation is required for three-dimensional flows. The present paper describes the progress of the validation of the k-ω turbulence model for two three-dimensional test cases. A case featuring Mach 4.5 air flow over a flat plate produced results that correlated with previous numerical results within 4%. A second case featuring the injection of Mach 1 air into a Mach 4 air cross-flow produced results indicating that the code successfully captured the main flow features.

scholarly journals A feature-based mesh adaptation for the unsteady high speed compressible flows in complex three-dimensional domains

2016 ◽  
Vol 40 (3) ◽  
pp. 1728-1740
Author(s):  
Hoang-Huy Nguyen ◽  
Vinh-Tan Nguyen ◽  
Matthew A. Price ◽  
Oubay Hassan
Keyword(s):  
High Speed ◽  
Compressible Flows ◽  
Three Dimensional ◽  
Mesh Adaptation ◽  
Feature Based

An Improved Hybrid Alternative WENO Scheme for High Mach Number Flows

2021 ◽  
Author(s):  
Uttam Singh Rajput ◽  
Krishna Mohan Singh
Keyword(s):  
High Speed ◽  
Compressible Flows ◽  
Weno Scheme ◽  
Test Cases ◽  
Present Scheme ◽  
Low Dissipation ◽  
Scale Structures ◽  
High Mach ◽  
Fifth Order ◽  
High Resolution Method

Abstract This study presents the development of a fifth-order hybrid alternative mapped weighted essentially non-oscillatory scheme (HAW-M) for high-speed compressible flows. A new, improved smoothness indicator has been developed to design the HAW-M scheme. The performance of the present scheme has been evaluated through different one and two-dimensional test cases. The developed scheme shows higher accuracy and low dissipation. Further, it captures the fine-scale structures smoothly than the existing high-resolution method.

scholarly journals Quasi-two-dimensional approximation for numerical simulation of flows in engine ducts

2019 ◽  
Author(s):  
V. Vlasenko ◽  
A. Shiryaeva
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Preliminary Design ◽  
Two Dimensional ◽  
Combustion Chambers ◽  
New Approach ◽  
One Dimensional ◽  
Dimensional Approximation ◽  
3D Flows

New quasi-two-dimensional (2.5D) approach to description of three-dimensional (3D) flows in ducts is proposed. It generalizes quasi-one-dimensional (quasi-1D, 1.5D) theories. Calculations are performed in the (x; y) plane, but variable width of duct in the z direction is taken into account. Derivation of 2.5D approximation equations is given. Tests for verification of 2.5D calculations are proposed. Parametrical 2.5D calculations of flow with hydrogen combustion in an elliptical combustor of a high-speed aircraft, investigated within HEXAFLY-INT international project, are described. Optimal scheme of fuel injection is found and explained. For one regime, 2.5D and 3D calculations are compared. The new approach is recommended for use during preliminary design of combustion chambers.

Simulation of the subsonic flow in a high-speed centrifugal compressor impeller by the pressure-based method

1998 ◽  
Vol 212 (4) ◽  
pp. 269-287 ◽  
Author(s):  
Y Wang ◽  
S Komori
Keyword(s):  
High Speed ◽  
Compressible Flows ◽  
Incompressible Flows ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
Navier Stokes Equations ◽  
Compressor Impeller ◽  
Collocated Grid

A pressure-based finite volume procedure developed previously for incompressible flows is extended to predict the three-dimensional compressible flow within a centrifugal impeller. In this procedure, the general curvilinear coordinate system is used and the collocated grid arrangement is adopted. Mass-averaging is used to close the instantaneous Navier-Stokes equations. The covariant velocity components are used as the main variables for the momentum equations, making the pressure-velocity coupling easier. The procedure is successfully applied to predict various compressible flows from subsonic to supersonic. With the aid of the k-ɛ turbulence model, the flow details within a centrifugal impeller are obtained using the present procedure. Predicted distributions of the meridional velocity and the static pressure are reasonable. Calculated radial velocities and flow angles are favourably compared with the measurements at the exit of the impeller.

All-Mach Number Density Based Flow Solver for OpenFOAM

2014 ◽  
Author(s):  
Martin Heinrich ◽  
Rüdiger Schwarze
Keyword(s):  
High Speed ◽  
Guide Vane ◽  
Time Integration ◽  
Three Dimensional ◽  
Measurement Data ◽  
Test Cases ◽  
Ansys Fluent ◽  
Upwind Schemes ◽  
Time Stepping ◽  
Computational Performance

A density-based solver for turbomachinery application is developed based on the central-upwind schemes of Kurganov and Tadmor using the open source CFD-library OpenFOAM. Preconditioning of Weiss and Smith is utilized to extend the applicability down to the incompressibility limit. Implicit residual averaging, bulk viscosity damping and local time stepping are employed to speed up the simulations. A low-storage 4-stage Runge-Kutta scheme and dual time-stepping are used for time integration. The presented solver is compared with results from ANSYS Fluent 13.0 and measurement data. Three different test cases are conducted to analyze different flow conditions: The circular bump for low and high speed inviscid flows and computational performance assessment, the two-dimensional VKI turbine guide vane for viscous flows and the the three-dimensional DLR high speed centrifual compressor validating the performance for rotating turbo-machinery. All three test cases show a very good agreement between OpenFOAM and ANSYS Fluent.

Investigations on Energy Shares and Flow Structures of the Mixing Flow Using 3D-POD Analyses

2019 ◽  
Author(s):  
Daekyeong Kong ◽  
Gyeongrae Cho ◽  
Myoung-Jin Kim ◽  
Deog Hee Doh ◽  
Sangmo Kang ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Flow Structures ◽  
Optical Encoder ◽  
Energy Distributions ◽  
Three Dimensional Flow ◽  
Mixing Properties ◽  
Vortical Structures ◽  
Flow Features ◽  
Proper Orthogonal

Abstract The objective of this report is investigate the influences of the mixing state to the productions of the vaterite crystal of CaCO3. In order to quantify the three-dimensional flow structures and their physical contribution to the mixing properties, a stereoscopic PIV (SPIV) has been adopted. The SPIV systems consists of two high speed cameras and an optical encoder which is used for trigging the SPIV system to capture the instantaneous flow images. A continuous laser (550nm) has been used. For mixing, an agitator having four blades has been used. The mixing tank has been filled with water up to 85% level of the tank height. The agitator has been rotated with 200rpm, 250rpm and 300rpm, and the 3D flow structures have been captured by the constructed SPIV system. Using measured instantaneous 3D vectors, POD (proper orthogonal decomposition) analyses has been adopted to investigate the energy distributions of the major vortical structures, and to evaluate the flow features regarding on the production of the vaterite crystal of CaCO3.

ON THE V2-BASED TURBULENCE MODEL FOR FREE-STREAM AND WALL-BOUNDED HIGH-SPEED COMPRESSIBLE FLOWS

2019 ◽  
Vol 46 (6) ◽  
pp. 565-578
Author(s):  
Alexander M. Molchanov ◽  
Dmitry S. Yanyshev ◽  
Leonid V. Bykov ◽  
Ivan M. Platonov
Keyword(s):  
Turbulence Model ◽  
High Speed ◽  
Compressible Flows ◽  
Free Stream

scholarly journals Simulation of Pharyngeal Airway Interaction with Air Flow Using Low-Re Turbulence Model

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
M. R. Rasani ◽  
K. Inthavong ◽  
J. Y. Tu
Keyword(s):  
Turbulence Model ◽  
Air Flow ◽  
Three Dimensional ◽  
Lagrangian Description ◽  
Three Dimensional Model ◽  
Pharyngeal Airway ◽  
Partitioned Approach ◽  
Flow Features ◽  
Airway Opening ◽  
Sst Turbulence Model

This paper aims to simulate the interaction between a simplified tongue replica with expiratory air flow considering the flow in the pharyngeal airway to be turbulent. A three-dimensional model with a low-Re SST turbulence model is adopted. An Arbitrary Eulerian-Lagrangian description for the fluid governing equation is coupled with the Lagrangian structural solver via a partitioned approach, allowing deformation of the fluid domain to be captured. Both the three-dimensional flow features and collapsibility of the tongue are presented. In addition, examining initial constriction height ranging from 0.8 mm to 11.0 mm and tongue replica modulus from 1.25 MPa to 2.25 MPa, the influence of both of these parameters on the flow rate and collapsibility of the tongue is also investigated and discussed. Numerical simulations confirm expected predisposition of apneic patients with narrower airway opening to flow obstruction and suggest much severe tongue collapsibility if the pharyngeal flow regime is turbulent compared to laminar.

scholarly journals On the Collapse Structure of an Attached Cavity on a Three-Dimensional Hydrofoil

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
Evert-Jan Foeth ◽  
Tom van Terwisga ◽  
Cas van Doorne
Keyword(s):  
High Speed ◽  
Mixing Layer ◽  
Three Dimensional ◽  
Leading Edge ◽  
High Speed Camera ◽  
Cavitation Tunnel ◽  
The University ◽  
Twisted Hydrofoil

A three-dimensional twisted hydrofoil with an attached cavitaty closely related to propellers was observed with a high-speed camera at the University of Delft Cavitation Tunnel. Reentrant flow coming from the sides of the cavity aimed at the center plane—termed side-entrant flow—collided in the closure region of the cavity, pinching off a part of the sheet resulting in a periodic shedding. The collapse of the remainder of the sheet appears to be a mixing layer at the location of the colliding reentrant flows. Collision of side-entrant jets in the closure region of a cavity is identified as a second shedding mechanism, in addition to reentrant flow impinging the sheet interface at the leading edge.

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