NATO-AVT-331 on "Goal-driven, multi-fidelity approaches for military vehicle system-level design"

L2 Sea Benchmark (developed by CNR-INM)

Andrea Serani and Matteo Diez

[Paper] [Presentation] [Video]

Tool description

• The tool provides the calm-water resistance of the DTMB-5415 (model scale) at Fr=0.28 by a linear potential flow solver.
• The tool is implemented in fortran and works under linux on windows linux subsystem by GNU or Intel fortran compilers.
• External libraries (lapack and blas for GNU or mkl for Intel) are needed.
• OpenMP implementation is also available but not mandatory.

Compilation options

• To compile the code,

  -- add the following line at the end of the .bashrc file ulimit -s unlimited

  -- open the makefile and

    -> for Intel compiler, uncomment the following compiling options
        FC       = ifort
        FCOPT    = -O5
        FCOPTOMP = -qopenmp
        LIB      = -mkl
    
    -> for GNU compiler, uncomment the following compiling options
        FC       = gfortran   
        FCOPT    = -O3
        FCOPTOMP = -fopenmp
        LIB      = -llapack -lblas
    
    !!!! ALLERT: under window linux subsystems make sure you are able to use openMP environment, otherwise comment the FCOPTOMP option   
  

  -- save and close the makefile and finally type make in a linux shell

Notes

• The potential flow solver can be run at even keel or with 2DoF. For the bechmark pourpouse the simulation can be performed at even and keel and the example file are already set up.

• Up to 7 fidelity levels have been defined.

• Only two text files (SBDF.nml and variables.inp) need to be edited to run the code.

-- SBDF.nml contains all the namelists

-> to select the fidelity levels, the parameters to be edited in the MAIN_PARAMETERS namelist is
    
    igrid           = 7				! Grid/fidelity level, 1=highest	(int)
    
-> variables.inp contains the design variables
    
    it is a column text files of 14 lines, each of them represents the design variable value and have to be within -1 and 1

• Run the code in the directory with the input files (see the /example/DTMB-5415 folder) executing the binary file in the /bin folder.

• A CPU000 folder will be created with all the input and output files. The objective function value, along with the costraints can be found in the objective.out file

References

References are available in the /doc folder. For the design-space and optimization problem definitions, constraints, and solver refer to

• Pellegrini, R., Serani, A., Liuzzi, G., Rinaldi, F., Lucidi, S., & Diez, M. (2022). A Derivative-Free Line-Search Algorithm for Simulation-Driven Design Optimization Using Multi-Fidelity Computations. Mathematics, 10(3), 481.
• Serani, A., Stern, F., Campana, E. F., & Diez, M. (2021). Hull-form stochastic optimization via computational-cost reduction methods. Engineering with Computers, 1-25.
• Serani, A., Diez, M., Wackers, J., Visonneau, M., & Stern, F. (2019). Stochastic shape optimization via design-space augmented dimensionality reduction and rans computations. In AIAA SciTech 2019 Forum (p. 2218).