Richard Barnwell

Professor Emeritus

Professional History

1995-present, Professor, Aerospace and Ocean Engineering, Engineering Science and Mechanics, Virginia Polytechnic Institute and State University; 1969-1995, Adjunct Professor, George Washington University; 1992-1993, Visiting Professor, Old Dominion University; 1993-1995, Aerodynamics Manager, High Speed Research Project, NASA; 1991-1993, Associate Division Chief, 1987-1991, Chief Scientist, 1978-1987, Group Leader, Branch Head, Assistant Division Chief, 1964-1978, Aerospace Engineer, NASA Langley Research Center.

Professional Leadership

Virginia Polytechnic Institute and State University Resident Faculty Member at the Virginia Consortium of Engineering and Science Universities, which provides a resident Ph.D. program in Hampton, VA; AIAA Fluid Mechanics Technical Committee; Reviewer for the Journal of Aircraft and AIAA Journal; AIAA Fellow.

Research Interests

Turbulence Modeling

Slip velocity concepts can be used in Navier-Stokes computation of turbulent wall-bounded flows to reduce computational grid requirements and remove or reduce the dependence on inner-layer eddy-viscosity models. The underlying analysis is based on the defect formulation for turbulent flow and relies on a law-of-the-wall model in the inner region.
Turbulence models are approximations which result because there are an insufficient number of equations to determine the unknowns. These models, which may be algebraic or differential, employ closure coefficients to relate properties. Sensitivity analysis, which is currently widely used in optimization, can be used also in model development as a means of evaluating model parameters and minimizing their number. Current research involves the use of automatic differentiation to evaluate the sensitivity of parameters used in two-equation turbulence models.

Multidisciplinary Analysis and Optimization

This research involves the extension of a recently developed unstructured-grid aerodynamic analysis and optimization code for three-dimensional configurations of interest to perform discrete sensitivity analysis using the direct differentiation approach. This code will be combined with an existing structural analysis code in order to develop a multidisciplinary optimization method.

Rotorcraft Aerodynamics

The development of flight performance predictions for rotorcraft has lagged behind that for fixed wing aircraft due to the complexity of the unsteady rotorcraft flowfield. However, substantial progress has been made on predicting the unsteady performance of the isolated rotor and on steady approximations to the rotor-fuselage interaction problem. The present research involves the development of a method for estimating rotor-fuselage interaction effects which incorporates a state-of-the-art unsteady rotor performance model.