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Hosny, W. M.

Publications and source records attributed to Hosny, W. M..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Dynamic data acquisition, reduction, and analysis for the identification of high-speed compressor component post-stability characteristics

A compressor test was conducted in which transient data were obtained for the purpose of identifying the high-speed post-stability characteristics. The transient, surge-cycle nature of high-speed post-stability operation precludes the possibility of obtaining the characteristics in a steady-state manner, as is possible during low-speed poststability operation, which is characterized by quasi-steady rotating-stall behavior. Specialized compressor instrumentation was developed and was used to obtain the necessary surge-cycle performance data, which were then digitized, filtered, and analyzed. The high-speed post-stability characteristics were obtained through the use of a maximum likelihood-parameter estimation technique. The estimated characteristics were found to be insensitive to the presence of measurement noise and unmodelled system dynamics, but the compressor time-response constants, which were also estimated, were more sensitive to these same disturbances.

Dvorak, S. D.↗
NASA NTRS1986

Aerodynamic instability performance of an advanced high-pressure-ratio compression component

The data acquisition and reduction, test procedures, and results of in-stall and in-surge testing of a NASA high-pressure-ratio compression component are discussed, in addition to the compressor-rig configuration and instrumentation used. Data analysis revealed information about rotating stall hysteresis, rotating stall development and cessation times, and rotating-stall-cell flow blockage. It is found that hysteresis exists in the work coefficient as well as in the pressure coefficient. Airflow rakes were designed to study the in-surge transient response of the compressor. The quasi-steady compressor characteristics underlying the transient-surge data were investigated using a parameter-identification technique.

Hosny, W. M.↗
NASA NTRS1980

Aerodynamic stability analysis of NASA J85-13/planar pressure pulse generator installation

A digital computer simulation model for the J85-13/Planar Pressure Pulse Generator (P3 G) test installation was developed by modifying an existing General Electric compression system model. This modification included the incorporation of a novel method for describing the unsteady blade lift force. This approach significantly enhanced the capability of the model to handle unsteady flows. In addition, the frequency response characteristics of the J85-13/P3G test installation were analyzed in support of selecting instrumentation locations to avoid standing wave nodes within the test apparatus and thus, low signal levels. The feasibility of employing explicit analytical expression for surge prediction was also studied.

Chung, K.↗
NASA NTRS1979

TF34 engine compression system computer study

The stability of the fan and the compressor components was examined individually using linearized and time dependent, one dimensional stability analysis techniques. The stability of the fan core integrated compression system was investigated using a two dimensional compression system model. The analytical equations on which this model was based satisfied the mass, axial momentum, radial momentum, and energy conservation equations for flow through a finite control volume. The results gave an accurate simulation of the flow through the compression system. The speed lines of the components were reproduced; the points of instability were accurately predicted; the locations where the instability was initiated in the fan and the core were indicated; and the variation of the bypass ratio during flow throttling was calculated. The validity of the analytical techniques was then established by comparing these results with test data and with results obtained from the steady state cycle deck.

Hosny, W. M.↗
NASA NTRS1977

Numerical solution for the temperature distribution in a cooled guide vane blade of a radial gas turbine

A two dimensional finite difference numerical technique is presented to determine the temperature distribution of an internal cooled blade of radial turbine guide vanes. A simple convection cooling is assumed inside the guide vane blade. Such cooling has relatively small cooling effectiveness at the leading edge and at the trailing edge. Heat transfer augmentation in these critical areas may be achieved by using impingement jets and film cooling. A computer program is written in FORTRAN IV for IBM 370/165 computer.

Hosny, W. M.↗
NASA NTRS1975

Flow behavior in inlet guide vanes of radial turbines

Scroll flow is discussed. Streamline pattern and velocity distribution in the guide vanes are calculated. The blade surface temperature distribution is also determined. The effects of the blade shapes and the nozzle channel width on the velocity profiles at inlet to the guide vanes are investigated.

Sokhey, J.↗