Martínez-Martí, Enrique G.

Profile Picture

Filters

20061
Reset filters

Settings

Citations

Publication Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Publication
    Flow and entropy characteristics around airfoils in subsonic and supersonic flows
    (2006) Martínez-Martí, Enrique G.; Raj-Pandya, R. Vikram; College of Engineering; Venkataraman, Nellore; Gutiérrez, Gustavo; Department of Mechanical Engineering; Castillo, Paul
    The presented research work analyzes numerically the flow characteristics such as density, pressure, and temperature at subsonic and supersonic speeds for flows past airfoils and explain their difference. Also, it analyzed the usage of the Entropy Generation Rate as a viable and effective way to design and model aerospace airfoils under different atmospheric environments. The goal of this research is to study the flow characteristics and the steady entropy production due to friction and heat transfer. To accomplish these goals, a wedge, a diamond wedge, and three different supercritical airfoils, the NACA 64215, the Grumman K2, and the Whitcomb Supercritical Integral Airfoil were studied. To verify the accuracy of the numerical program, an inviscid supersonic flow past a wedge at Mach 2.6 was analyzed to verify the accuracy of the Computation Fluid Dynamics (CFD) program. Two of the airfoils were analyzed at five different Mach numbers, while the third one was analyzed at four different Mach numbers. The flow characteristics and the entropy generation for the NACA 64215 and the K2 were investigated at five different speeds. Four of the speeds, Mach 0.3, 0.6, 2.0, and 3.0, were similar for all the airfoils at standard atmospheric conditions while the last speed varied depending on the experimental data taken from wind tunnels. These Mach number were selected in order to have two subsonic cases and two supersonic cases. The viscous diamond wedge airfoil was analyzed only at Mach 0.6 and Mach 2.0 and at an angle of attack (alpha) of one degree to compare its entropy generation rate with the entropy generation from the three airfoils. The entropy generation rate was determined by using the results obtained from the NASA CFL3D CFD program and input those results into a Fortran program that was done for this thesis. CFL3D is a structured grid CFD solver program that analyzes the time dependent conservation form of the Reynolds-Averaged thin-layer Navier-Stokes equations. It uses a semi-discrete finite-volume approach in order to spatially discretized the formulas with upwind-biasing for the convective and pressure terms and central differencing for the shear stress and heat transfer terms. An implicit method is used in order to advance in time and solving for either steady or unsteady flows. Experimental data is used to validate the results of the program.