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Paul Danehy

Publications and source records attributed to Paul Danehy.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

TPSAS-NF1676L-23344-DND

This presentation gives an overview of the biography of Dr. Walter Lempert who was employed by NASA Langley in the 1980's and then was a researcher at The Ohio State University.

Naibo Jiang↗
NASA NTRS2015

Molecular-Based Optical Diagnostics for Hypersonic Nonequilibrium Flows

This presentation package consists of seven different talks rolled up into one. These talks are all invited orals presentations in a special session at the Aviation 2015 conference and represent contributions that were made to a recent AIAA book that will be published entitled 'Hypersonic Nonequilibrium Flows: Fundamentals and Recent Advances'. Slide 5 lists the individual presentations that will be given during the special session.

Paul Danehy↗
NASA NTRSDate not supplied

TPSAS-NF1676L-13662-DND

Nonintrusive spectral analysis of high enthalpy hypersonic flow, simulating atmospheric entry, was produced for passive and ablative heat shield materials. A calibrated fiber-optic coupled spectrometer was use to determine shock structure and prominent radiative chemical species.

Drew Hires↗
NASA NTRSDate not supplied

TPSAS-NF1676L-14351-DND

Why hypervelocity scramjets? - Airbreathing effective specific impulse (Isp) - Increase Two Stage to Orbit (TSTO) staging Mach number Hypervelocity challenges: - Many, in all disciplines (e.g. materials), primarily due to high enthalpy flow - Most challenging propulsion system: scramjet combustor (combustor residence time ~ 1 ms)

Maxwell DePiro↗
NASA NTRSDate not supplied

TPSAS-NF1676L-18762-DND

This presentation gives a broad overview of spectroscopic measurement techniques for aerospace flows. Among the topics discussed are LIF, CARS, and molecular tagging velocimetry. Examples of the use of these techniques in real-world applications are given.

Paul Danehy↗
NASA NTRSDate not supplied

From Wind Tunnels to Flight Vehicles: Visualization and quantitative measurements supporting NASA’s space program

NASA’s Space Launch System (SLS) and Orion Crew Module have been studied in wind tunnels using the planar laser-induced fluorescence (PLIF) technique for flow visualization and quantitative thermometry and in flight using high-resolution imagery and quantitative infrared surface heating measurements. This paper reviews both types of measurements. OCIS codes: (120.1740) Combustion diagnostics; (300.2530) Fluorescence, laser-induced; (110.3080) Infrared imaging.

Planar Laser-Induced Fluorescence (PLIF)↗
NASA NTRSDate not supplied

Evaluation of CFD for Simulation of High-Supersonic Control Surface Effectiveness

This is the set of slides describing the CFD and wind-tunnel test studying the control surfaces of the CobraMRV concept for entry, descent, and landing on Mars. Difference between the CFD and wind-tunnel results are highlighted with the intent of showing whether CFD can replace wind-tunnel testing in the high supersonic flight regime.

wind tunnel↗
NASA NTRSDate not supplied

10-kHz PLIF Thermometry for Turbulent Jet Flame using Single Burst-mode OPO

Two-color Planar Laser-Induced Fluorescence (TC-PLIF) thermometry techniques that employ two laser systems and two cameras face challenges when implemented in practical combustion facilities because of experimental complexity and multiple laser and camera requirements, particularly for high-speed TC-PLIF. To circumvent those problems, we developed a fast, dual-wavelength switching, burst-mode OPO technology to significantly reduce the experimental complexity of high-speed TC-PLIF thermometry and simplify its implementation in harsh combustion and flow test facilities. A fast, dual-wavelength switched seed laser enabled a high-energy, high-repetition-rate burst-mode laser to generate two 10-kHz pulse trains at wavelengths of ~354.8 nm. The injection-seeded OPO efficiently converts the burst-mode laser output to 285.62 nm and 285.67 nm to excite the Q2(12) andP1(8) OH transitions. PLIF images were collected from each of the two excitation transitions with a single camera and an UV intensifier, and intensity ratios from the images were used to determine local temperatures. Ten kHz hydroxyl radical (OH) TC-PLIF for premixedCH4/Air/H2 jet flame was demonstrated.

thermometry↗
NASA NTRSDate not supplied

Characterization of Naturally-Occurring Particles in the NASA Langley 0.3-m Transonic Cryogenic Tunnel Using PTV

Naturally-occurring particles within the NASA Langley 0.3-m Transonic Cryogenic Tunnel are characterized for their aerodynamic performance using particle tracking velocimetry. Two sets of experiments were conducted to observe different behaviors of the particles. The normal shockwave emanating from the top surface of a supercritical airfoil was used to induce velocity lag in the particles, and the subsequent spatial decay of the velocity was used to estimate the effective diameter of the particles. Mean particle diameters between 1.6 and 1.9 𝝁m were measured, with sizes ranging from 0.2 to 3.5 𝝁m over the entire ensemble. The response of particles to separated flow was investigated. By operating in “high-lift” (low Mach number, high angle of attack) conditions with a semi-span airfoil, the ability of particles to detect separated flow on the upper surface of the airfoil was assessed. Transition from fully attached flow to fully separated flow was observed on the top surface of the airfoil accompanying a variation of angle of attack from 8° to 12°. Examination of velocity distributions indicates less than 10 percent of particle trajectories did not respond to the regions of separated flow. These results are promising, but further facility-specific work is needed to answer the broader question of particle tracking reliability.

Transonic↗