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Reinath, M. S.

Publications and source records attributed to Reinath, M. S..

11 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

A laser-sheet flow visualization technique for the large wind tunnels of the National Full-Scale Aerodynamics Complex

A flow visualization technique for the large wind tunnels of the National Full Scale Aerodynamics Complex (NFAC) is described. The technique uses a laser sheet generated by the NFAC Long Range Laser Velocimeter (LRLV) to illuminate a smoke-like tracer in the flow. The LRLV optical system is modified slightly, and a scanned mirror is added to generate the sheet. These modifications are described, in addition to the results of an initial performance test conducted in the 80- by 120-Foot Wind Tunnel. During this test, flow visualization was performed in the wake region behind a truck as part of a vehicle drag reduction study. The problems encountered during the test are discussed, in addition to the recommended improvements needed to enhance the performance of the technique for future applications.

Reinath, M. S.↗
NASA NTRS1986

Experimental study of flow deflectors designed to alleviate ground winds induced by exhaust of 80-by 120-foot wind tunnel

An experimental study directed at finding a deflector ramp that will reduce to an acceptable level the ground winds under the exhaust jet of the 80 by 120 Foot Wind Tunnel at NASA Ames Center is described. A one-fifieth scale model of the full-scale facility was used to investigate how the jet flow field was modified by the various design parameters of the ramp. It was concluded that the ground winds were alleviated sufficiently by a ramp with end plates located next to the wind tunnel building along the ground edge of the exhaust opening. At full scale, the ramp should have a slant length of 7.62 m (25 ft) or more, and would be elevated at about 45 degrees to the ground plane. The material should have holes less than 15.2 (6 in) in diameter distributed uniformly over its surface to produce a porosity of about 30%.

Rossow, V. J.↗
NASA NTRS1985

Prediction of the flow-field interference induced by the long-range laser velocimeter in the Ames 40- by 80-foot and the 80- by 120-foot wind tunnels

The predicted flow disturbances induced in the test sections of the Ames 40- by 80-Foot Wind Tunnels by the presence of the Long-Range Laser Velocimeter (LRLV) are presented. The predictions were made using a potential-flow paneling code to model the test section and the LRLV, and a calculation of the resulting flow field was made. The flow velocity and angularity were calculated at numerous locations in the flow field relative to the LRLV, and the results are presented.

Reinath, M. S.↗
NASA NTRS1985

Nonsimultaneous coupled laser velocimeter measurement technique: Error prediction for spatially noncoincident measurements

A technique for obtaining orthogonal velocity components from nonorthogonal measurements using the NASA Ames Research Center Long-Range Laser Velocimeter (LRLV) is briefly discussed. A description is then presented of the error that occurs when these nonorthogonal measurements are spatially noncoincident because of positioning inaccuracies, and equations are developed for predicting this error. Sample data are presented and a prediction of the expected error for two typical applications is made. To cover other cases in general, a parametric study is conducted and the results are presented in a tabular format.

Reinath, M. S.↗
NASA NTRS1984

A laser velocimeter system for large-scale aerodynamic testing

A unique laser velocimeter was developed that is capable of sensing two orthogonal velocity components from a variable remote distance of 2.6 to 10 m for use in the 40- by 80-Foot and 80- by 120-Foot Wind Tunnels and the Outdoor Aerodynamic Research Facility at Ames Research Center. The system hardware, positioning instrumentation, and data acquisition equipment are described in detail; system capabilities and limitations are discussed; and expressions for systematic and statistical accuracy are developed. Direct and coupled laboratory measurements taken with the system are compared with measurements taken with a laser velocimeter of higher spatial resolution, and sample data taken in the open circuit exhaust flow of a 1/50-scale model of the 80- by 120-Foot Wind Tunnel are presented.

Reinath, M. S.↗
NASA NTRS1984

Laser velocimetry in the low-speed wind tunnels at Ames Research Center

The historical development of laser velocimetry and its application to low-speed (less than 100 m/sec) aerodynamic flows in the subsonic wind tunnels at Ames Research Center is reviewed. A fully three dimensional velocimeter for the Ames 7- by 10-Foot Wind Tunnel is described, and its capabilities are presented through sample data from a recent experiment. Finally, a long-range (2.6 to 10 m) velocimeter that is designed to be installed within the test section of the Ames 40- by 80-Foot Wind Tunnel is described and sample data are presented.

Orloff, K. L.↗
NASA NTRS1984

A laser velocimeter system for the Ames 40- by 80-foot and 80by 120-foot wind tunnels

A unique laser velocimeter has been developed that is capable of sensing two orthogonal velocity components from a variable remote distance of 2.6 to 10 m for use in the Ames 40- by 80-Foot and 80- by 120-Foot wind tunnels, as well as in the Ames Outdoor Aerodynamic Research Facility. The system hardware, positioning instrumentation, and data acquisition equipment are described in detail. System capabilities and limitations are discussed, and expressions for systematic and statistical accuracy are developed. Direct and coupled laboratory measurements of a turbulent swirling flow are compared with measurements taken with a laser velocimeter of higher spatial resolution. Sample measurements taken in the open-circuit exhaust flow of the 80- by 120-Foot Wind Tunnel 1/50-scale model are presented.

Reinath, M. S.↗
NASA NTRS1984

Laser velocimetry in the low-speed wind tunnels at Ames Research Center

The historical development of laser velocimetry and its application to low-speed (less than 100 m/sec) aerodynamic flows in the subsonic wind tunnels at Ames Research Center is reviewed. A fully three-dimensional velocimeter for the Ames 7- by 10-Foot Wind Tunnel is described, and its capabilities are presented through sample data from a recent experiment. Finally, a long-range (2.6 to 10 m) velocimeter that is designed to be installed within the test section of the Ames 40- by 80-Foot Wind Tunnel is described and sample data are presented.

Orloff, K. L.↗
NASA NTRS1983

Reduction of flow-measurement uncertainties in laser velocimeters with nonorthogonal channels

An analysis of certain geometrical limitations inherent in the application of laser velocimeters with nonorthogonal channels has led to the development of advanced-LDA-calibration and data-acquisition techniques that minimize systematic and statistical errors, respectively. The data-acquisition technique optimizes the number of velocity samples collected from three velocimeter channels as a function of local turbulence intensity, vector direction, and prescribed confidence interval. Linear velocity surveys and streamline traces measured in a turbulent flow field with a three-dimensional laser velocimeter are presented and the validity and accuracy of the theoretical analysis are discussed.

Snyder, P. K.↗
NASA NTRS1982

Laser velocimeter for large wind tunnels

The measurement of velocity in large wind tunnels is normally performed using mechanical probes. This practice can entail considerable complexity in connection with the structure often required for probe support. The use of laser velocimetry for the flowfield measurements in large wind tunnels is, therefore, far more desirable since it can be implemented with minimal mechanical complexity and with minimal modifications to the test section structure. A description is provided of a velocimeter which is intended for use in investigations which include V/STOL vehicle flowfield mapping for location and sizing of wakes and plumes, wing-loading distribution determination without the need for pressure taps, the aerodynamics of high-lift airfoils as well as rotating rotor blades, and vehicle wake studies. Use is made of a single-color dual-beam backscatter system which is capable of sensing two orthogonal components of velocity.

Reinath, M. S.↗