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Wu, J. M.

Publications and source records attributed to Wu, J. M..

27 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Measurements of compressible secondary flow in a circular S-duct

This paper presents the results of an experimental study of secondary flow in a circular cross section 30 deg - 30 deg S-duct with entrance Mach number of 0.6. Local flow velocity vectors have been measured along the length of the duct at six stations. These measurements have been made using a five-port cone probe. Static and total pressure profiles in the transverse planes are obtained from the cone probe measurements. Wall static pressure measurements along three azimuth angles of 0 deg, 90 deg, and 180 deg along the duct are also made. Contour plots presenting the three dimensional velocity field as well as the total- and static-pressure fields are obtained. Surface oil flow visualization technique has been used to provide details of the flow on the S-duct boundaries. The experimental observations have been compared with typical computational results.

Vakili, A.↗
NASA NTRS1983

Viscous flow behavior of four iron-containing silicates with alumina, effects of composition and oxidation condition

The viscosity of a magma is an important parameter in connection with its effect on geologic processes such as melt segregation, magma vesiculation, and crystal fractionation. Though most models of geologic processes assume relatively low values for the magma viscosity less than 10,000 poise, it would be useful to have an empirical model for estimating viscosities when the process occurs during continuous cooling to a temperature region where the viscosity is expected to be very high. The considered work has been carried out to provide the experimental measurements of viscosity at low temperatures which would be used in formulating the empirical model. Ten iron-containing silicate compositions have been investigated by Klein et al. (1981), and four of these compositions have been selected for the present study with alumina. The study involves substitutions of Al2O3 for FeOx at Na2O/Al2O3 moles greater than one. For the four iron-containing silicate glasses with alumina, the viscosity at a given temperature is found to increase with increasing (Fe + Al).

Klein, L. C.↗
NASA NTRS1982

Three-dimensional flow studies on a slotted transonic wind tunnel wall

Three-dimensional flow field measurements were made near a transonic slotted wall. Field velocity vectors and static pressure distributions have been obtained. The boundary layer displacement thickness was found to vary in the transverse plane with its maximum at the slot center line but decreased with increasing suction rate through the slot. The boundary layer characteristics were sensitive to the mass transfer through the slot. The projection on the flow field velocity vectors on the transverse plane reveals a vortex-like flow formation. The center of this secondary flow was located nearly at the edge of the wall shear layer and decreased in strength with applied suction. The secondary vortex motion may be attributed to the mean flow skewing, inhomogeneous transverse plane boundary layer and the wall turbulence anisotropy.

Wu, J. M.↗
NASA NTRS1982

Flow behavior of ten iron-containing silicate compositions

The viscosity of ten iron-containing silicates has been measured over the temperature range 400 to 650 C. The compositions contain trace amounts up to 30 wt. pct. or 20 mole. pct. Fe3O4 from 10 to 20 wt. pct. or 10 to 20 mole. pct. Na2O and the remainder is SiO2. Samples were melted in air to form oxidized samples, in forming gas (95% N2-5% H2) to form mildly reduced samples, and in forming gas with carbon in the batch to form strongly reduced samples. In general, the viscosity decreased with increasing mole. pct. Na2O and decreasing mole. pct. SiO2 for a given temperature. In samples with increasing mole. pct. FeO(x) the difference in the viscosity between the oxidized sample and the reduced sample grew in magnitude at a given temperature. In all of the compositions, the log or viscosity, vs reciprocal-of-temperature relation shows curvature with an apparent activation energy between 90 and 100 kcal/mole.

Klein, L. C.↗
NASA NTRS1981

Aerodynamic interaction of heat transfer with steady transonic flow

An experimental study investigated the interactive effect between the heat transfer and the steady transonic flow in a simple convergent-divergent duct. The results show that the position of the shock is considerably affected by the effect of wall cooling. The physical explanation for the shift is also offered. The results may have implications in the other internal flow problems.

Kurosaka, M.↗
NASA NTRS1975

Numeric calculation of unsteady forces over thin pointed wings in sonic flow

A fast and reasonably accurate numerical procedure is proposed for the solution of a simplified unsteady transonic equation. The approach described takes into account many of the effects of the steady flow field. The resulting accuracy is within a few per cent and can be carried out on a computer in less than one minute per case (one frequency and one mode of oscillation). The problem concerns a rigid pointed wing which performs harmonic pitching oscillations of small amplitude in a steady uniform transonic flow. Wake influence is ignored and shocks must be weak. It is shown that the method is more flexible than the transonic box method proposed by Rodemich and Andrew (1965) in that it can easily account for variable local Mach number and rather arbitrary planform so long as the basic assumptions are fulfilled.

Kimble, K. R.↗
NASA NTRS1974

Numerical solution for unsteady sonic flow over thin wings

A numerical solution precedure of a simplified unsteady transonic equation which is fast, reasonably accurate, and takes into account many of the effects of the steady flow field is described. The numeric solution of this equation is accurate and is accomplished on an IBM 360/65 computer. Arbitrary planform shape is accommodated and variable local Mach number effects from the steady flow are easily handled.

Kimble, K. R.↗
NASA NTRS1973

Unsteady transonic flow analysis for low aspect ratio, pointed wings.

Oswatitsch and Keune's parabolic method for steady transonic flow is applied and extended to thin slender wings oscillating in the sonic flow field. The parabolic constant for the wing was determined from the equivalent body of revolution. Laplace transform methods were used to derive the asymptotic equations for pressure coefficient, and the Adams-Sears iterative procedure was employed to solve the equations. A computer program was developed to find the pressure distributions, generalized force coefficients, and stability derivatives for delta, convex, and concave wing planforms.

Kimble, K. R.↗