At the CSLab at UAB, we emphasis on the implementation and validation of state ot the art algorithms for computational field simulations.  We have developed in-house CFD, CSM, FSI, and MDO related codes and modules for this purpose.  The in-house codes provides a framework for testing new algorithms as well as provides an opportunity for students to gain experience in code development and learn software development principles.

## In-House Codes

#### HYB3D

• Density-based Reynolds-Averaged Navier-Stokes Flow Solver
• Finite Volume, Upwind Scheme
• Generalized Grid Topology
• Cell-Centered Scheme– control volume: cell
• Convective Flux
• Roe’s Approximate Riemann Solver
• Spatial Accuracy
• Second Order: Linear Reconstruction Based on Taylor’s Series with Limiter functions
• Implicit Viscous terms
• Grid Speed Terms and Geometrical Conservation Law (GCL)
• Linear Reconstruction Scheme
• ­Weighted averaging procedure and Green’s theorem
• Least square fit (weighted or unweighted)
• Time Integration
• Explicit scheme: four stage Runge-Kutta method
• Implicit scheme:
• Jacobians: approximate analytical or numerical
• Block sparse matrix system
• Symmetric Gauss-Seidel as matrix solver
• Turbulence Model
• Spalart-Allmaras One-Equation Turbulence Model
• DES Model
• K-omega Model

#### FDNS-RVF

• Pressure-based Reynolds-Averaged Navier-Stokes Flow Solver
• Finite Difference/Finite Volume Approach
• Predictor/Multi-Corrector Solution Scheme
• Euler Implicit and Crank-Nicolson Time Marching for Transient Flow Simulation
• High-Order Upwind/TVD and Central Difference Schemes, Adaptive Dissipation for Convection Terms
• Multi-Zone/Multi-Block, Body-fitted Coordinate, Structure Grid Topology
• Point-by-Point, Conjugate Gradient, or GMRES Matrix Solvers
• Finite-Rate and Equilibrium Chemistry Models
• Eulerian-LaGrangian Particle Tracking Method
• Heterogeneous/Homogeneous Spray Model
• Turbulence Models:
• Two-equation eddy viscosity models
• Various corrections for compressibility effects
• Multi-scale hybrid RANS/LES
• Conjugate Heat Transfer
• Surface Pyrolysis Model
• Porosity Model
• Parallel Computing:
• PVM (Parallel Virtual Machine)
• MPI (Message-Passing Interface)

#### NXAIR

NXAIR is an overset-structured grid 3D Navier-Stokes solver that is the workhorse code for unsteady flow and moving body problems at AEDC. The code is a perfect gas density-based flow solver. Some features of the code includ:

• Third order MUSCL spatial upwind HLLE flux calculation
• First or second order time
• Full or thin-layer Navier-Stokes
• Global Newton iteration designed for unsteady applications
• Several implicit solvers are available:
• Red-black Jacobi
• SSOR
• Multigrid with any of the above algorithms
• Grid Sequencing for convergence acceleration
• Parallel using MPI
• Preconditioning for low speed applications
• Accelerating reference coordinate systems
• Geometric conservation law (GCL) for deforming grids
• Multiple turbulence models are available:
• Baldwin-Lomax model
• Spalart-Allmaras model
• k-e model
• k-w model
• Menter’s two-equation SST model
• Spalart’s Detached Eddy Simulation (DES) model
• Multi-Scale hybrid RANS/LES model
• SST DES model
• Compressible wall function boundary condition option for both adiabatic and constant temperature walls for the one-equation and two-equation turbulence models
• 2D, axisymmetric, and 3D options.
The code has been run on a number of parallel computing platforms including SGI O2Ks and O3Ks, HP Exemplars and Superdomes, IBM SP3s and SP4s, COMPAQ, SUN, and Linux clusters. The code has been used to support a number of weapons systems in the past few years including:

#### SMDOC

• Statistical Multi-objective Design Optimization Code
• Response surface methodology (Global approximation of system behavior by linear, elliptic or quadratic polynomial)
• Adaptive to any kind of experimental design
• Singular value decomposition algorithm to solve singular matrix from certain type of experimental design
• Error analysis (Residual sum of squares, Maximum residual, Prediction error, Prediction sum of squares residual)
• Method of feasible direction for constrained optimization
• Multi-start local optimization to find a global optimum point
• Multi-objective optimization techniques
• Utility function formulation, Global Criterion formulation, Game theory approach

## Commercial Codes

#### HyperWorks Version 9.0 (commercial code, Altair Engineering, Troy, MI):

HyperMesh

A high-performance finite element pre- and post-processor for major finite element solvers, allowing engineers to analyze design conditions in a highly interactive and visual environment. HyperMesh’sHyperMesh allow users to optimize meshes from a set of quality criteria, change existing meshes through morphing and generate mid-surfaces from models of varying thickness. user-interface is easy to learn and supports the direct use of CAD geometry and existing finite element models, providing robust interoperability and efficiency. Advanced automation tools within

HyperView

A complete post-processing and visualization environment for finite element analysis (FEA), multi-body system simulation, video and engineering data. Amazingly fast 3D graphics and unparalleled functionality set a new standard for speed and integration of CAE results post-processing. HyperView enables you to visualize data interactively as well as capture and standardize your post-processing activities using process automation features. HyperView also saves 3D animation results in Altair’s compact H3D format so you can visualize and share CAE results within a 3D web environment using Altair HyperView Player.

HyperForm

A unique finite element based sheet metal forming simulation software solution. HyperForm combines an extremely fast one-step solver and incremental forming solution with the customized geometry manipulation and mesh generation capabilities of HyperMesh. HyperForm provides engineers at any stage of product design with quick, valuable, reliable information, reducing the overall product cycle. HyperForm’sHyperView, HyperForm can export data in the Altair .h3d format allowing results to be visualized using HyperView Player with any web browser. die module takes a giant leap in bringing the product designer closer to manufacturing by enabling engineers to create and analyze conceptual die designs in order to generate an optimized die. Die concepts can then be read into any CAD system as a starting block for the actual die build. Integrated with Altair

HyperViewPlayer, HyperGraph and MotionView are also available

A general purpose transient dynamic finite element program capable of simulating complex real world problems such as automotive crashworthiness and occupant safety, sheet metal forming (metal stamping, hydroforming, forging, deep drawing, multi-stage processes), military and defense applications (penetration (projectile and armor), explosives, weapon design, underwater simulations, waste containment), aerospace industry applications (blade containment, bird strike (windshield, and engine blade), failure analysis), and other applications (drop testing, can and shipping container design, electronic component design, glass forming, plastics, mold, and blow forming, biomedical, metal cutting, earthquake engineering, failure analysis, sports equipment (golf clubs, golf balls, baseball bats, helmets), civil engineering (offshore platforms, pavement design)).

A general purpose finite element modeling package for numerically solving a wide variety of mechanical problems. These problems include: static/dynamic structural analysis (both linear and non-linear), heat transfer and fluid problems, as well as acoustic and electromagnetic problems.

An advanced engineering software tool that allows users to design and optimize world-wide standard for occupant safety analysis. It is used extensively in industrial engineering, design offices, research laboratories and technical universities. It has proven itself in numerous applications, often supported by verification studies using experimental test data. By using Multibody and Finite Element techniques together, users have the flexibility to create a wise variety of restraint systems. MADYMO also provides specialized options such as advanced seat belt systems, and a number of thermodynamic options for modeling airbags. Interfaces between MADYMO and third-party explicit finite element packages are available. MADYMO allows users to design and optimize the vehicle structures, components and safety systems at the very start of the development track – thereby minimizing the need of costly and time-consuming mechanical prototypes.

#### PATRAN Version 2001 (commercial code, MSC, Santa Ana, CA):

An open-architecture, general purpose, 3-D mechanical computer aided-engineering (MAE) software package with interactive graphics providing a complete CAE environment for linking engineering design, analysis, and results evaluation functions. In manufacturing companies throughout industry, MSC.Patran is the acknowledged leading finite element modeler, enabling the user to conceptualize, develop and test a product through computer-based simulation prior to making manufacturing and material commitments. MSC.Patran brings the full power of mechanical simulation to the design process for reduced cost, increased productivity and faster time to market.

As part of Virtual Product Development (VPD) process, user can use MSC.Nastran to assess many functional aspects of one’s products, such as the structural response (displacement, strain, stress, vibration, temperature) due to its material properties and the loads and boundary conditions that are applied to it during operation. The MSC.Nastran product family is modular, enabling to analyze products ranging from simple components to complex structures and systems. This also enables to start simply and to grow analysis capabilities as VPD needs progress. The Basic product configuration enables to perform linear statics, normal modes, and buckling analyses on models of unlimited size. When users want to extend and accelerate FEA work, user can add products tailored to Heat Transfer, Dynamics, Spot Welding, Aeroelasticity, or Nonlinear analyses. And user can automate or customize user’s work using the Optimization or DMAP products, respectively.