Engineer Engineering

David D. Chao

*** * ******* *****

Wichita, KS **206

Home 316-***-****

acwf5e@r.postjobfree.com

Experience

Industry Engineer Contractor November 2013 – July 2016 PDS Tech Engineering Services, Irving, TX 75063

Provided engineering support to Textron Aviation's Scorpion program.

• Iteratively designed multiple scoops to satisfy systems and manufacturing constraints while meeting or exceeding target mass flow rates. Also assessed aerodynamic impact from other design, manufacturing, or system requirements and proposed solutions to mitigate undesirable effects.

• Resolved discrepancies in certain aircraft performance parameters from analysis of flight test data, wind tunnel data, and CFD simulations.

• Conducted aerodynamic analysis of aircraft or aircraft components using CFD, analytical, or empirical methods for other engineering groups. This included supplying limit pressure data and/or aerodynamic forces and moments over a range of flight conditions, siting probes and vanes, and calculating hinge forces/moments as some examples.

• Incorporated quasi-linear method using CFD for predicting pitch-damping coefficients.

• Completed preliminary nacelle design for Hemisphere business jet. Aerodynamics Engineer October 2009 – April 2013

Vestas Technology R & D Americas, Inc., Houston, TX 77002 Emphasis of work was on developing and maturing tools and technologies for wind turbine blade applications. Other responsibilities included coordinating and supporting wind tunnel tests and developing project business cases and plans.

• Developed an empirical, best practice guideline for designing vane vortex generators to reduce flow separation along an airfoil. Also designed the wind tunnel study to validate this approach but was not implemented.

• As Technical Lead, organized a project team of 4-5 members to meet milestones ahead of a major technical review with key stakeholders while also conducting technical work and coordinating with project manager to develop business case and plans.

• Co-technical monitor for joint wind tunnel study with Texas A&M University investigating leading edge roughness modeling and vortex generator effects on airfoil performance.

• Member of project team which developed several technologies and design methodologies for retrofitting devices such as Gurney flaps, vortex generators, and blade tip extensions onto existing blades to improve flow control and boost energy production by 1-4%.

• Member of project team which developed an integrated CFD package for designing and analyzing airfoils and blades. Responsibilities included incorporating surface roughness and vortex generator effects into XFOIL, directly modeling vortex generators on a span section, and benchmarking and validating CFD results.

• Member of team which conducted airfoil optimization studies from design to wind tunnel validation.

• Researched and compiled numerous comparative surveys of aerodynamic and aeroacoustic features to assess potential state-of-the-art performance on wind turbines including but not limited to winglets, serrated trailing edges, and blade surface features.

• Co-inventor (patent): Wind Turbine Blade and Method for Manufacturing a Wind Turbine Blade with Vortex Generators

• Co-inventor (patent-pending): Noise Attenuator for a Wind Turbine Blade and a Method for Reducing Wind Turbine Noise

Senior Engineer May 2007 – October 2009

Engineer October 2005 – May 2007

Cessna Aircraft Company, Wichita, KS 67215

Focus was on applied computational aerodynamics to the design, development, and analysis of aircraft and aircraft components. Provided support and guidance for wind tunnel tests, flight tests, and to other engineering groups. Assignments included but not limited to:

• Multi-point optimization of Citation CJ4 and Columbus nacelle designs using potential (VSAERO) and Euler (NSU3D) methods. Resulting intake design for CJ4 was flight tested at over 99% efficiency.

• Multi-point optimization of Columbus pylon design to minimize shocks and satisfy structural constraints while also factoring in simultaneous effects from evolving designs of wing and tailcone sections. Final design exhibited a weak shock only for high-speed cruise condition.

• Coordinated with propulsion/systems/airframe groups to minimize aerodynamic impacts from thrust reverser integration and ducting/piping issues on the Columbus nacelle and pylon.

• Coordinated with systems/airframe groups and third-party vendors to determine optimal positioning of probes and vanes on aircraft fuselage.

• 2D parametric optimization of slat and flap positions for takeoff and landing configurations using viscous analysis (NSU2D).

• Analysis of wing tip designs using potential methods (VSAERO and TRANAIR) to increase aircraft range and performance.

• Multi-point optimization of airfoils using MSES/LINDOP for numerous projects.

• Analysis of scoop designs and internal flows using STAR-CCM+ to avoid or minimize flow separation.

• Analysis of computational and flight test data to assist determination of loads and icing requirements.

Research Research Consultant April 2004 – September 2005 University of California, Davis, Davis, CA 95616

TPI Composites, Inc., Warren, RI 02885

Sandia National Laboratories, Albuquerque, NM 87185 Applied methods of computational fluid dynamics to evaluate the rotational effect on the flow and the performance characteristics of thick blade-root section shapes. Airfoil sections along part of the blade were also modified with increasing maximum thickness-to-chord ratios and blunt trailing-edge thicknesses to assess aerodynamic impact. Results indicated thicker airfoils with blunt trailing edges can be designed to alleviate structural requirements without sacrificing structural integrity or aerodynamic performance.

Research Consultant April 2001 – September 2001

University of California, Davis, Davis, CA 95616

The Wind Turbine Company, Bellevue, WA 98015

Analyzed the time-accurate dynamics of a cylinder in various cross-flow conditions using computational fluid dynamics. Investigated the consistency and accuracy of solutions on different grid topologies (O-grids and Chimera grids) through the analysis of time-averaged values and shedding frequencies. Results were used to determine if practical solutions existed to reduce noise and blade fatigue due to blade/wake interaction for downstream turbine designs. Publications and Presentations

"Advanced Aerodynamic Modeling of Vortex Generators for Wind Turbine Applications," S. Xue, B. Johnson, D. Chao, A. Sareen, C. Westergaard, European Wind Energy Conference and Exhibition 2010, Warsaw, Poland, April 2010.

"RaNS Analysis of an Inboard Flatback Modification to the NREL Phase VI Rotor," D.D. Chao and C.P. van Dam, AIAA-2006-0195, 44th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 2006.

"Innovative Structural and Aerodynamic Design Approaches for Large Wind Turbine Blades," C.P. van Dam, E.A. Mayda, D.D. Chao, K.J. Jackson, M.D. Zuteck, and D. Berry, AIAA-2005- 0973, 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 2005.

"Wing Drag Prediction and Decomposition," D.D. Chao and C.P. van Dam, AIAA-2004-5074, 22nd Applied Aerodynamics Conference and Exhibit, Providence, RI, August 2004.

"Airfoil Drag Prediction and Decomposition," D.D. Chao and C.P. van Dam, Journal of Aircraft, Vol. 36, No. 4, July/August 1999, pp. 675-681.

"Navier-Stokes Analysis of Time-Dependent Flows about Wind Turbines," E.P.N. Duque, C.P. van Dam, R.R. Brodeur, and D.D. Chao, 3rd ASME/JSME Joint Fluids Engineering Conference, San Francisco, CA, July 1999.

"Airfoil Drag Prediction and Decomposition," D.D. Chao and C.P. van Dam, AIAA-1998-2783, 16th Applied Aerodynamics Conference, Albuquerque, NM, June 1998. Also presented paper further detailing methods and results of predicting the aerodynamic performance of two airfoils in subsonic and transonic flows.

"Drag Prediction for Airfoils in Viscous Transonic Flow," C.P. van Dam and D.D. Chao, Proceedings of Advances in Flow Simulation Techniques, University of California, Davis, May 1997, pp. 288-300.

Education

2004 Ph.D., Aeronautical Science and Engineering

University of California, Davis Davis, CA 95616

Dissertation: Drag Prediction and Decomposition for Airfoils and Wings 1997 M.S., Aeronautical Science and Engineering

University of California, Davis Davis, CA 95616

Thesis: Subsonic and Transonic Drag Prediction of Single-Element Airfoils Using Navier-Stokes Solutions

1994 B.S., Aeronautical Science and Mechanical Engineering University of California, Davis Davis, CA 95616

Other Training and Experience

Pointwise

FUN3D

Tecplot

Fortran

R

XFOIL / MSES

OVERFLOW

NSU2D / NSU3D

VSAERO

Fluent

AVL (Athena Vortex Lattice)

ICEM-CFD

Catia v5

VGRID

Linux (basic command line operations and scripting)

Windows (Word, Excel, PowerPoint, Outlook)

Other Information

U.S. citizen with current passport

Open to relocation

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