Type of Awards: SBIR Phase I and Phase II Subcontractors: Mezzo Technologies and Honeywell Aerospace Contract Numbers: FA8650-08-M-2843 and FA8650-09-C-2400 Agency: U.S. Air Force Research Laboratory Status: On Going Periods: 9/18/07 to 9/18/08 and 5/28/09 to 9/13/11 Principal Investigator: A. Heltzel Abstract: The current thermal management effort for high performance aircraft focuses much attention on more efficient energy rejection through the development of advanced heat exchanger technologies. PC Krause and Associates (PCKA) is currently filling a much-needed gap of scaling and performance knowledge in the Air Force Phase I SBIR effort. 3-D computational fluid dynamics models have been constructed, which have been shown to accurately predict microstructured heat sink performance where conventional analysis methods fail. The ability to collapse high-fidelity data into a performance database is allowing PCKA to develop a rapid analysis software package for advanced heat exchangers. In Phase II, PCKA will team with both Honeywell Aerospace and Mezzo Technologies Inc., two manufacturers of candidate heat exchangers. This collaboration will enable the application of the analysis tool to near-term heat exchanger design projects, in addition to providing validation, manufacturing, and non-core effect information to the analysis method. PCKA will expand the modeling and simulation effort to encompass additional heat exchanger designs, materials, working fluids, operating conditions, and the true dynamic response of candidate heat exchangers. The software tool to be developed in Phase II directly addresses the stated goal of this project: accelerating the design concept to development to fabrication...
Read MoreEfficient Multi-Scale Radiation Transport Modeling
Type of Awards: SBIR Phase I Contract Numbers: NNX09CF07P Agency: NASA Glenn Research Center Status: On Going Periods: 1/22/09 to 7/22/09 Principal Investigator: A. Heltzel Abstract: Focusing on a reduced-dimension problem of a hypersonic orbital/lunar reentry capsule, an algorithm will be built which combines the stochastic Monte Carlo method for treatment of radiation transport in optically thin to moderate domains, with a single-term modified differential approximation (MP1) for use in optically thick domains. This numerical method will be verified against a known benchmark case before application to the reentry problem. The bandwise and cumulative distribution function (CDF) methods will be combined within the Monte Carlo framework, creating an efficient, dual-hybrid radiation transport algorithm. A detailed plan for the generation of the full algorithm will be developed, with a focus on parallelization and compatibility with existing commercial transport software. This plan will include thorough testing and validation...
Read MoreSimulation of Electromagnetic Field Distribution at a Nanowire Probe for Near Field Scanning Optical Microscopy
N. P. Malcolm, Department of Mechanical Engineering, University of Texas at Austin; A. Heltzel, PC Krause and Associates, Inc; L. Shi, J. R. Howell, Department of Mechanical Engineering, University of Texas at Austin ASME Micro/Nanoscale Heat Transfer International Conference, Tainan, Taiwan, 2008.
Read MoreDynamic Thermal Management System Modeling of a More Electric Aircraft
K. McCarthy, E. A. Walters, A. Heltzel, PC Krause and Associates, Inc; R. Elangovan, G. Roe, W. Vannice, Boeing; C. Schemm, Lockheed Martin; J. Dalton, Avetec; S. Iden, P. Lamm, C. Miller, U.S. Air Force Research Laboratory; A. Susainathan, U.S. Air Force Aeronautical Systems Center Advancements in electrical, mechanical, and structural design onboard modern more electric aircraft have added significant stress to the thermal management systems (TMS). A thermal management system level analysis tool has been created in MATLAB/Simulink to facilitate rapid system analysis and optimization to meet the growing demands of modern aircraft. It is anticipated that the tracking of thermal energy through numerical integration will lead to more accurate predictions of worst case TMS sizing conditions. In addition, the nonproprietary nature of the tool affords users the ability to modify component models and integrate advanced conceptual designs that can be evaluated over multiple missions to determine the impact at a system level. 2008 SAE Power Systems Conference, November 11-13 2008, Bellevue, WA. Paper...
Read MoreSimulation of a Plasmonic Tip-Terminated Scanning Nanowire Waveguide for Molecular Imaging
Nathan P. Malcolm, Department of Mechanical Engineering, University of Texas at Austin; A. Heltzel, PC Krause and Associates, Inc; Konstantin V. Sokolov, Department of Biomedical Engineering, University of Texas M.D. Anderson Cancer Center; Li Shi and John R. Howell, Department of Mechanical Engineering, University of Texas at Austin Finite difference time domain simulation reveals plasmonic coupling and local field enhancement at the gap between the gold nanoparticle _NP_ tip of a ZnO nanowire _NW_ waveguide and a gold-coated substrate or a gold NP probe. The region of field enhancement is about three times smaller than the 100 nm diameter of the gold NP tip, making the NW waveguide grown on a transparent microcantilever well-suited for near field imaging of single molecules immobilized on a gold substrate or gold NP-labeled cell membranes with superior spatial resolution and signal to noise ratio. 2008 American Institute of Physics. _DOI:...
Read MoreOptoelectronic Property Modeling of Carbon Nanotubes Grafted with Gold Nanoparticles
A. Heltzel, PC Krause and Associates, Inc; Liangti Qu, Liming Dai, University of Dayton Research Institute A three-dimensional (3D) electrodynamic model is built using the finite-difference time-domain (FDTD) method to investigate the optical response of carbon nanotubes grafted with gold nanoparticles. Theoretical characterizations suggest an anisotropic response, in line with previously observed absorption peaks of such systems in the optical range. An investigation of geometric and wavelength dependences is conducted, predicting the ability to tune the sub-wavelength intensity enhancement for efficient localization and propagation. The support of electric field enhancement along the nanotube walls raises the possibility of utilizing such systems as plasmon generators and waveguides for optical signal propagation. Online at...
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