The Automatic Generation of Adjoint Solutions for a General Purpose Flow Solver

2008 ◽  
Author(s):  
D Hill
Keyword(s):  
Automatic Generation ◽  
General Purpose ◽  
Flow Solver ◽  
Adjoint Solutions

A General Purpose Parallel Block Structured Open Source Flow Solver

2012 ◽  
Author(s):  
Mariana Mendina ◽  
Martin Draper ◽  
Gabriel Narancio ◽  
Gabriel Usera ◽  
Ana Paula Kelm Soares
Keyword(s):  
Open Source ◽  
General Purpose ◽  
Flow Solver ◽  
Source Flow ◽  
Block Structured

scholarly journals Interpretation of Adjoint Solutions for Turbomachinery Flows

2012 ◽  
Author(s):  
Sriram Shankaran ◽  
Andre Marta ◽  
Prem Venugopal ◽  
Brian Barr ◽  
Qiqi Wang
Keyword(s):  
Flow Field ◽  
Adjoint Equations ◽  
Flow Solver ◽  
Low Pressure Turbine ◽  
Compressor Rotor ◽  
Performance Metric ◽  
Physical Insight ◽  
End Wall ◽  
Adjoint Solutions ◽  
Design Guidance

While the mathematical derivation of the adjoint equations and their numerical implementation is well established, there is a scant discussion on the understanding of the adjoint solution by itself. As this is a field solution of similar resolution of the flow-field, there is a wealth of data that can be used for design guidance. This paper addressess this specific topic. In particular, we take representative cases from turbomachinery aerodynamic problems and use the adjoint solution to identify the “physical insight” it provides. We aim to tie the adjoint solution to the flow-field which has physical properties. Towards this end, we first look at three problems 1) a fan, 2) a compressor rotor and stator, 3) a low pressure turbine. In all three of them, we focus on changes related to geometry, but one can also realize the changes using other inputs to the flow solver (eg. boundary conditions). We show how the adjoint counter-part of the density, the velocity fields and the turbulence quantities can be used to provide insights into the nature of changes the designer can induce to cause improvement in the performance metric of interest. We also discuss how to use adjoint solutions for problems with constraints to further refine the changes. Finally, we use a problem where it is not immediately apparent what geometry changes need to be used for further evaluation with optimization algorithms. In this problem, we use the adjoint and flow solution on a turbine strut, to determine the kind of end-wall treatments that reduce the loss. These changes are then implemented to show that the loss is reduced by close to 8%.

scholarly journals Fluid Flow and Heat Transfer Prediction in a Non-Rotating Axial Turbine Internal Coolant Passage and Comparison With Experiment

1993 ◽  
Author(s):  
W. N. Dawes ◽  
A. J. White
Keyword(s):  
Heat Transfer ◽  
General Purpose ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Transfer Coefficients ◽  
Absolute Level ◽  
Flow Solver ◽  
Heat Transfer Coefficients ◽  
Flow And Heat Transfer ◽  
Unstructured Meshing

This paper describes the application of an unstructured mesh, solution-adaptive, 3D Navier-Stokes solver to the numerical simulation of the flow in a complex, three pass, turbulated, serpentine coolant passage, typical of modern axial gas turbine practice. The predicted variation of heat transfer coefficient on the convex, pressure side of the passage is in encouraging agreement with measurements from a very similar geometry, particularly as regards spatial distribution. The absolute level of the predicted heat transfer coefficients is somewhat lower than in the measurements but this is consistent with the post-processing difficulty of defining the temperature difference used to form the coefficient. A strong inter-relationship was observed between the secondary flows in the coolant passage and the heat transfer distribution. The paper attempts to show that the benefits of unstructured meshing, solution-adaption and a general purpose flow solver combine to produce a very powerful analytical ability which now permits routine solution of complex geometries such as that described here.

scholarly journals A Symbolic Approach to the Multibody Modeling of Road Vehicles

2017 ◽  
Vol 09 (05) ◽  
pp. 1750068 ◽  
Author(s):  
Roberto Lot ◽  
Matteo Massaro
Keyword(s):  
Equations Of Motion ◽  
Automatic Generation ◽  
General Purpose ◽  
Rigid Bodies ◽  
Simulation Code ◽  
Symbolic Form ◽  
Multibody Modeling ◽  
Mixed Coordinates ◽  
Computer Algebra Software ◽  
Symbolic Approach

This paper introduces MBSymba, an object-oriented language for the modeling of multibody systems and the automatic generation of equations of motion in symbolic form. MBSymba has built upon the general-purpose computer algebra software Maple and it is freely available for teaching and research purposes. With MBSymba, objects such as points, vectors, rigid bodies, forces and torques, and the relationships among them may be defined and manipulated both at high and low levels. Absolute, relative or mixed coordinates may be used, as well as combination of infinitesimal and noninfinitesimal variables. Once the system has been modeled, Lagrange’s and/or Newton’s equations can be derived in a quasi-automatic way, either in an inertial or noninertial reference frame. Equations can be automatically converted into Matlab, C/C++ or Fortan code to produce stand alone, numerically optimized simulation code. MBSymba is particularly suited for the modeling of ground, water or air vehicles; therefore, the mathematical model of a passenger car with trailer is illustrated as a case study. Time domain simulations, steady state analysis and stability results are also presented.

General Dynamic Model of Flexible Multi-Body Systems With Its Application in Gun Systems

2003 ◽  
Author(s):  
GuoLai Yang ◽  
Yunsheng Chen
Keyword(s):  
Dynamic Model ◽  
Dynamic Simulation ◽  
Equations Of Motion ◽  
Automatic Generation ◽  
General Purpose ◽  
Automatic Identification ◽  
Automatic Modeling ◽  
Kane’S Equation ◽  
Multi Body ◽  
General Dynamic

General purpose software for kinematic and dynamic simulation of flexible multi-body systems is serviced widely to practical engineering fields. In this paper general dynamic model of flexible multi-body systems with its application in gun systems is set up vie Kane’s equation. The “0-1” method is presented for calculating partial velocities, partial angular velocities and coefficients matrix of the differential equations of motion. Techniques of automatic modeling for dynamic analysis of flexible multi-body systems of gun systems are introduced in this paper, which include automatic identification of systems configuration, automatic determination of degrees of freedom, automatic derivation of kinematic formulas, automatic application of load, automatic generation and solution of motion equations and so on. Because of automatic modeling, overelaborate procedures are avoided, and model on general purpose is realized, which can be conveniently used in dynamic simulation for launching process of gun systems and validly applied to design of them. Finally, a numerical example is given to demonstrate the feasibility of general algorithms proposed.

Heat Exchanger Analysis Combining 1-D and 3-D Flow Modeling

2005 ◽  
Author(s):  
Vincent De Henau ◽  
Iftekhar Ahmed
Keyword(s):  
Heat Exchanger ◽  
Transfer Problem ◽  
Solution Process ◽  
Integrated Approach ◽  
General Purpose ◽  
Duct Flow ◽  
Coupled Flow ◽  
Flow Solver ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer

A recently developed method that couples a 1-D duct flow solver to a 3-D general purpose Computational Fluid Dynamics (CFD) solver is described. This methodology provides an integrated approach for the solution of coupled flow and heat transfer problem, utilizing 1D and 3D meshes for fluid flow. During the solution process, principles of conservation are preserved at the interface of the two flow domains. Results from the coupled 1D/3D simulation are then verified by comparison to the 3D solution, and are validated against an empirically obtained correlation for a shell and tube heat exchanger.

A general purpose parallel block structured open source incompressible flow solver

2013 ◽  
Vol 17 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Mariana Mendina ◽  
Martin Draper ◽  
Ana Paula Kelm Soares ◽  
Gabriel Narancio ◽  
Gabriel Usera
Keyword(s):  
Open Source ◽  
Incompressible Flow ◽  
General Purpose ◽  
Flow Solver ◽  
Block Structured

A Parallel Implementation of General Purpose Unstructured Flow Solver

2002 ◽  
Author(s):  
Padma Mallapragada ◽  
Sijun Zhang ◽  
Jiwen Liu ◽  
Yen-Sen Chen ◽  
Dinesh Godavarty
Keyword(s):  
Parallel Implementation ◽  
General Purpose ◽  
Flow Solver
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