EDUCATION

B.S. Aerospace Engineering University of Maryland 1977
B.S. Mathematics University of Maryland 1977
M.S. Aeronautics & Astronautics Stanford University 1978
Ph.D. Aeronautics & Astronautics Stanford University pending

EXPERIENCE

1987-1997

RESEARCH SCIENTIST, Flow Analysis, Inc., 256 93rd St., Brooklyn, N.Y. 11209.

(1994-97) Developed the FPXBVI CFD code for the NASA Langley TRAC (Tilt-rotor Aeroacoustics Code) program. Modified the previously developed FPX code to incorporate all vortex element modeling from the FPRBVI code. Presently incorporating blade-motion modeling, internal grid generation, and coupling software for use of the acoustics code RKIR.
 

(1992-93)Worked on the development of the Vorticity Confinement method, with particular emphasis on application to compressible flows. The method yields a velocity correction term which acts to counter numerical diffusion and improve the preservation of vortical structures. Developed a code module called CONFINE and combined it with the Euler/Navier- Stokes rotor code TURNS to create TURNS-CONFINE. Applications include the development and convection of wing-tip vortices, airtbil-vortex interactions, and hovering helicopter rotors.

SENIOR RESEARCH ENGINEER, Woodside Summit Group, 658 Bair Island Blvd., Redwood City, CA,

(1994-96) Incorporated the Vorticity Embedding method into the rotorcraft CFD code FPX. Applied the new code to loads predictions of blade- vortex-interact ions. Extensive validation comparisons were made to experimental data taken in the NASA Ames Research Center 80x120 wind tunnel.

An acoustics capability was added to FPX by coupling the code to a rotating Kirchhoff prediction code. The FPX/Kirchhoff acoustics prediction code was applied to the prediction of both High- Speed-Impulsive and Blade-Vortex-- Interaction noise. HSI noise predictions were compared with experimental data for the OLS blade and BVI noise predictions were made for the aforementioned study,

(1989-93) Developed the code FPX, a multiple-topology version of the viscous rotor flow code, VIPER, previously developed for the Army Acroffightdynamics Directorate (AADD) at NASA Ames Research Center. During the major rewrite of the code, particular attention was devoted to efficiency considerations, ensuring a program that would run optimally on both vector and multiple processing systems (e.g. Cray-2, Cray Y-MP, etc.). Additional applications of the code are aimed towards the Tilt Rotor (in cruise condition, i.e., propeller mode), BVI, and aeroelasticity. In addition, developed improved coupling procedures, including the correct blade motion terms, for coupled CFD/Comprehensive rotorcraft analysis methods, Numerous algorithms improvements were included, including Newton sub-iteration.

(1988) Developed an improved viscous rotor flow code, VIPER for AFDD. The development of an improved potential code, FPR/v2.0, was assisted by the derivation of a consistent metric differencing scheme. The simulation of nonisentropic effects was improved by use of the exact one-dimensional steady formula for the entropy and a pressure coefficient expression which reflected the entropy term downstream of shocks, The computation of viscous effects were improved by coupling with a three-dimensional finite-difference boundary layer code (BL31).
 

(1987) Developed a viscous rotor flow code, FPRV, for the Army Aeroflightdynamics Directorate (AFDD) at NASA Ames Research Center. An inviscid, isentropic unsteady rotor code, FPR (based on the fixed wing code TUNA), was modified to include viscous effects. A steady two-dimensional integral boundary layer method for computing turbulent flows was coupled to FPR using a velocity transpiration boundary condition, Shock/boundary layer interaction effects were modeled using a viscous ramp method. In addition, entropy addition at shock waves was included, in order to more accurately model the correct shock jump conditions for strong shock waves. Numerous demonstration runs were performed to validate the methods.

1978-1980

RESEARCH SCIENTIST, Applied Computational Aerodynamics Branch, NASA Ames Research Center, Moffett Field, CA.

(1984-1986) Responsible for the development of a large computer program, TURNS, for simulating Transonic Unsteady viscous flow about Rotorcraft --using the three-dimensional Reynolds- averaged Navier-Stokes equations The suitability of existing viscous flow programs for the computation of steady, two-dimensional flows was thoroughly examined and reported on. A detailed analysis of the requisite computational facilities was also performed and reported on.

(1981-1983) Several versions of a computer code, TUNA, were developed for the simulation of two and three-dimensional Transonic Unsteady Aerodynamics, with emphasis on aeroelastic applications. An efficient, approximate-factorization finite difference algorithm was developed for solving the unsteady full potential equation. These codes were optimized (Fortran) for use on the Cray X-MP and CDC Cyber 205 supercomputers, This work represented the bulk of dissertation research. In addition, course requirements for the Ph.D. were completed at Stanford University.

(1979-1980) A von Karman Institute lecture entitled "Numerical Solution Techniques for Unsteady Transonic Aerodynamics Problems," was prepared The four hour lecture, consisting of 130 slides, was presented on March 13, 1980 at VKI in Belgium to a group representing the aerospace community form both the United States and Europe, The associated paper review the present state-of-the-art finite difference methods for solving the governing equations of unsteady transonic flow, the mathematical formulations used, fundamental concepts of finite difference methods, and example applications, The paper was subsequently published as an AGARD report.

(1978-1979) An existing computer code, LTRAN2, was used to conduct a detailed comparison between computed and experimental surface pressures for an airfoil oscillating in pitch in a transonic flow. The accuracy, range of validity, and major deficiencies of LTRAN2 were determined and modifications to the mathematical formulation and numerical algorithm were proposed to improve the comparisons.

Summer-1977

AEROSPACE ENGINEER, Mathematics and Engineering Branch, Naval Surface Weapons Center, Silver Spring, MD.

Aided in the development of a computer code for simulating viscous flow fields about re-entry vehicles. Several turbulence models were coded and tested.
 

PUBLICATIONS

1. ........... us, W.F., and Bridgeman, J.O., "Numerical Solution Techniques for Unsteady
    Transonic Aerodynamics Problems," presented at the AGARD Special Course on Un-
    ...........y Aerodynamics, von Karman Institute for Fluid Dynamics, Rhode-St-Genese, Bel-
    .........., March 10-14, 1980; also AGARD Report No. 679, June 1980.

2. Bridgeman J.0., Steger, J.L., and Caradonna, FX, "A Conservative Finite- Difference
    Algorithm for the Unsteady Transonic Potential Equation in Generalized Coordinates," &             AIAAPaper No. 82-1388, presented at the AIAA 9th Atmospheric Flight Mechanics Conference, San Diego, California, Aug. 1982.

3. ........Croskey, WSJ., Kutler, P., and Bridgeman, J.O., "Status and Prospects of
Computational Fluid Dynamics for Unsteady Transonic Viscous Flows," Paper No. 9, AGARD Conference Proceedings CP-974, September 1985.

4.  .......c Croskey, W.J., Baeder, J.D., and Bridgeman, J.O., "Calculation of Helicopter Airfoil     Characteristics for High Tip-Speed Applications," presented at the 41st Annual Forum of the American Helicopter Society, Fort Worth, Texas, May 1985; also AHS Journal, April 1986.

5. Bridgeman, J.O., Strawn, R.C., and Caradonna, FX, "An Entropy and Viscosity Corrected
    Potential Method for Rotor Pe~rformance Prediction," presented at the 44th Annual Forum of the American Helicopter Society, Washington, D.C., June 16-18, 1988.

6. Caradonna, FX, Strawn, R.C, and Bridgeman, J.O., "An Experimental and Computational Study of Rotor-Vortex Interactions, " presented at the Fourteenth European Rotorcraft Forum, Milano, Italy, September 20-23, 1988.

7. Bridgeman, J.O., Strawn, R.C., Caradonna, FX, and Chen, C.S., "Advanced Rotor Computations with a Corrected Potential Method," presented at the 45th Annual Forum of American Helicopter Society, Boston, Mass., May 22-24, 1989.

8 . .........hen, C.S., and Bridgeman, J.0., "Three- Dimensional Viscous Rotor Flow Calculations using Boundary-Layer Equations," presented at the 15th European Rotorcraft Forum, Amsterdam, the Netherlands, September 12-15, 1989.

9. Strawn, R.C., and Bridgeman, J.O., "An Improved Three- Dimensional Aerodynamics
Model for Helicopter Airloads Prediction," AIAA paper No. 91-0767, presented at the AIAA 29th Aerospace Sciences Meeting, Reno, Nevada, Jan. 7-10, 1991.

10. Bridgeman, J.O., Prichard, D., and Caradonna, FX, "The Development of a CFD Potential
      Method for the Analysis of Tilt-Rotors," paper presented at the AHSIRAes International         Technical Specialists Meeting on Rotorcraft Acoustics and Rotor Fluid Dynamics, Valley Forge,     Pennsylvania, October 15-17, 1991.

11. Wang, C.W., Bridgeman, J.O., Steinhoff, J.S,, and Wenren, Yonghu, "The Application of Computational Vorticity Confinement to Helicopter Rotor and Body Flows," presented at the American Helicopter Society 49th Annual Forum, St Louis, Missouri, May 19-21, 1993.

12. Bridgeman, J.O,, Ramachandran, K., Caradonna, FX, and Prichard, D., "A Computational Analysis of Parallel Blade-Vortex Interactions Using Vorticity Embedding," presented at the American Helicopter Society 50th Annual Forum, Washington, D.C., May 11 -13, 1994.

13. Bridgeman , J.O., Ramachandran, K., Caradonna, FX, and Prichard, D., "The Application of Vorticity Embedding to Parallel Blade-Vortex Interactions," presented at the 12th AIAA Applied Aerodynamics conference" Colorado Springs, CO, June 20-23, 1994.

14. Moulton, M.A., Bridgeman, J.0., and Caradonna, FX, "Development of an Over set/Hybrid CFD Method," presented at the American Helicopter Society 53th Annual Forum, Virginia Beach, Virginia, April 29 - May 1, 1997.

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