NCSI: The Effect of Convex Wall Curvature on Hypersonic Turbulent Boundary Layers

Status	Completed
Mentor Name	Guillermo Araya
Mentor's XSEDE Affiliation	XSEDE-allocation PI
Mentor Has Been in XSEDE Community	4-5 years
Project Title	The Effect of Convex Wall Curvature on Hypersonic Turbulent Boundary Layers
Summary	Turbulent boundary layers that evolve along the flow direction are ubiquitous. Computationally speaking, this type of boundary layer poses an enormous challenge, due to the need for accurate inflow turbulence information. Moreover, accounting for the effects of wall-curvature driven pressure gradient and flow compressibility adds significant complexity to the problem. Consequently, hypersonic spatially-developing turbulent boundary layers (SDTBL) over curved walls are of crucial importance in aerospace applications, such as unmanned high-speed vehicles, scramjets and advanced space aircrafts. This project seeks to evaluate the effect of convex surface curvature on spatially evolving turbulent boundary layers at hypersonic speeds (Mach number ~ 5). The main idea is to perform Reynolds Averaged Navier-Stokes (RANS) simulations and turbulence model assessment by means of a commercial Computational Fluid Dynamics (CFD) software, such as STAR-CCM+ or ANSYS-FLUENT, in moderate and strong Favorable Pressure Gradient (FPG) flows induced by wall curvature. Validation of numerical results will be done by comparison with a previously obtained Direct Numerical Simulation (DNS) database and wind tunnel experiments from the literature. This is a continuation Fall-2018 EMPOWER internship project.
Job Description	The intern position during Spring 2019 is at the High Performance Computing and Visualization Lab (HPCVL) www.uprm.edu/hpcvl/ at the Dept. of Mechanical Engineering in the U. of Puerto Rico-Mayaguez (UPRM). The undergraduate student intern will work on available commercial packages. The principal objectives/tasks of this internship can be summarized as follows: - Develop a computational model of a hypersonic flat plate (Zero Pressure Gradient ZPG flow) at low Reynolds numbers. - Develop a computational model of wind tunnel experiments at hypersonic speeds from the literature with convex wall curvature (FPG) at high experimental Reynolds numbers. - Perform RANS simulations of hypersonic ZPG and FPG flows by considering two popular turbulence models: Spalart-Allmaras and k-omega. - Post-process and validate numerical results against Direct Numerical Simulation (DNS) and wind tunnel experiments.
Computational Resources	The DNS database of a Mach-5 turbulent flat plate is stored in Ranch (TACC). These simulations were performed in Stampede2 under XSEDE computational allocation #TG-CTS170006. The intern will be set as a user of this account in order to get access to the TACC computational resources in order to post-process and extract DNS data for validation of the time-averaged flow obtained by RANS.
Contribution to Community
Position Type	Intern
Training Plan	The intern will initially receive training on compressible flow, shock/expansion waves, turbulence, data management, data transfer, C++ and Fortran at the HPCVL lab by the PI and other skilled students. A candidate from the underrepresented Hispanic community will be targeted during the hiring process with the main objective of encouraging him/her in pursuing STEM careers at a graduate level.
Student Prerequisites/Conditions/Qualifications	This intern level position is opened for undergraduate students at the University of Puerto Rico-Mayaguez. Candidates should have intermediate knowledge and skills on CFD commercial packages, preferable STAR-CCM+ or ANSYS-FLUENT. Basic knowledge of C++ and Fortran is desirable. A skilled intern has already been identified.
Duration	Semester
Start Date	01/15/2019
End Date	05/31/2019