NASA Scientific and Technical Aerospace Reports

prediction of time-dependent flows in the presence of an active flow control device. The configuration under consideration is
a synthetic jet created by a single diaphragm piezoelectric actuator in quiescent air. Time-averaged and instantaneous data for
this case were obtained at Langley Research Center, using multiple measurement techniques. Computational results for this
case using one-equation Spalart-Allmaras and two-equation Menter s turbulence models are presented here along with
comparisons with the experimental data. The effect of grid refinement, preconditioning and time-step variation are also
examined.
Author
Navier-Stokes Equation; Reynolds Averaging; Unsteady Flow; Computerized Simulation; Computational Fluid Dynamics;
Flow Regulators; Jet Flow; Air Flow
20040112057 NASA Langley Research Center, Hampton, VA, USA
An Implicit Upwind Algorithm for Computing Turbulent Flows on Unstructured Grids
Anerson, W. Kyle; Bonhaus, Daryl L.; Computers Fluids; [1994]; Volume 23, No. 1, pp. 1-21; In English; Original contains
black and white illustrations; Copyright; Avail: CASI; A03, Hardcopy
An implicit, Navier-Stokes solution algorithm is presented for the computation of turbulent flow on unstructured grids.
The inviscid fluxes are computed using an upwind algorithm and the solution is advanced in time using a backward-Euler
time-stepping scheme. At each time step, the linear system of equations is approximately solved with a point-implicit
relaxation scheme. This methodology provides a viable and robust algorithm for computing turbulent flows on unstructured
meshes. Results are shown for subsonic flow over a NACA 0012 airfoil and for transonic flow over a RAE 2822 airfoil
exhibiting a strong upper-surface shock. In addition, results are shown for 3 element and 4 element airfoil configurations. For
the calculations, two one equation turbulence models are utilized. For the NACA 0012 airfoil, a pressure distribution and force
data are compared with other computational results as well as with experiment. Comparisons of computed pressure
distributions and velocity profiles with experimental data are shown for the RAE airfoil and for the 3 element configuration.
For the 4 element case, comparisons of surface pressure distributions with experiment are made. In general, the agreement
between the computations and the experiment is good.
Author
Algorithms; Turbulent Flow; Unstructured Grids (Mathematics); Upwind Schemes (Mathematics); Airfoils
20040112059 NASA Langley Research Center, Hampton, VA, USA
Assessing the Capability of Doppler Global Velocimetry To Measure Vortical Flow Fields
Meyers, James F.; Usry, Jimmy W.; Miller, L. Scott; Journal of Aerospace Engineering; December 1994; Volume 208, Part
G, pp. 99-105; In English; Original contains color illustrations; Copyright; Avail: CASI; A03, Hardcopy
A new nonintrusive flow diagnostics instrumentation system, Doppler global velocimetry, is presented. The system is
capable of making simultaneous, three-component velocity measurements within a selected measurement plane at video
camera rates. These velocity images can provide the researcher with spatial and temporal information about the flow field in
a global sense. The investigation of a vortical flow above a 75-degree delta wing comparing standard three-component,
fringe-type laser velocimetry measurements with Doppler global velocimetry measurements is presented.
Author
Flow Distribution; Laser Doppler Velocimeters; Computational Fluid Dynamics; Wind Tunnel Tests
20040120931 NASA Marshall Space Flight Center, Huntsville, AL, USA
High Reynolds Number Thermal Stability Experiments
Emens, Jessica M.; Brown, Sarah P.; Frederick Robert A., Jr.; Wood, A. John; July 11, 2004; 9 pp.; In English; AIAA Joint
Propulsion Conference, 11-14 Jul. 2004, Fort Lauderdale, FL, USA
Contract(s)/Grant(s): NCC8-200
Report No.(s): AIAA Paper 2004-4089; No Copyright; Avail: CASI; A02, Hardcopy
This work represents preliminary thermal stability results for liquid hydrocarbon fuels. High Reynolds Number Thermal
Stability experiments with Jet A and RP-1 resulted in a quantitative measurement of the thermal stability. Each fuel flowed
through a heated capillary tube that held the outlet temperature at 290 C. An optical pyrometer measured the surface
temperature of the tube at 12 locations as a function of time. The High Reynolds Number Thermal Stability number was then
determined using standards published by the American Society for Testing and Materials. The results for Jet A showed lower
thermal stability than similar tests conducted at another facility. The RP-1 results are the first reported using this technique.
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