Navier-Stokes analysis of turbine blade heat transfer

Comparisons with experimental heat transfer and surface pressures were made for seven turbine vane and blade geometries using a quasi-three-dimensional thin-layer Navier-Stokes analysis. Comparisons are made for cases with both separated and unseparated flow over a range of Reynolds numbers and freestream turbulence intensities. The analysis used a modified Baldwin-Lomax turbulent eddy viscosity mode. Modifications were made to account for the effects of: (1) freestream turbulence on both transition and leading edge heat transfer; (2) strong favorable pressure gradients on relaminarization; and (3) variable turbulent Prandtl number heat transfer. In addition, the effect of heat transfer on the near wall model of Deissler is compared with the Van Driest model

Computer program for thermal analysis of shadow shields in a vacuum

Computer program determines temperature profiles and heat transfer rates for shadow shielded cryogenic tank. Tank, shields, and thermal radiation heat source are all axisymmetric. Thermal analysis considers varying shield and tank temperatures, surface properties, and geometric arrangements. Similar heat source properties are also considered

Analytic and experimental evaluation of shadow shields and their support members for thermal control of space vehicles

The thermal performance of shadow shields, and their support struts, for the thermal protection of cryogenic propellants in a simulated deep-space environment was investigated analytically and experimentally. Very low overall heat-transfer rates were obtained when highly reflective aluminized Mylar shadow shields were used. The thermal interactions between the shields and support struts were investigated with fair to good agreement between the analysis and experimental data. The exterior surface of both fiberglass and titanium struts was coated to reduce the heat input into the test tank. The vacuum level inside the test facility strongly influenced the heat-transfer rates

An analytical and experimental evaluation of shadow shields and their support members

Experimental tests were performed on a model shadow shield thermal protection system to examine the effect of certain configuration variables. The experimental results were used to verify the ability of an analytical program to predict the shadow shield performance including the shield-support interaction. In general, the analysis (assuming diffuse surfaces) agreed well with the experimental support temperature profiles. The agreement for the shield profiles was not as good. The results demonstrated: (1) shadow shields can be effective in reducing the heat transfer into cryogenic propellant tanks, and (2) the conductive heat transfer through supports can be reduced by selective surface coatings

Use of the booklet category test to assess abstract concept formation in schizophrenic disorders

The relationship of concept formation abilities to the presence or absence of delusions in schizophrenic disorders was investigated. Twenty-six schizophrenic patients and 14 normal individuals were administered a short form of the Booklet Category Test (BCT). Patients were grouped into those with and without delusions. It was hypothesized that the delusional group would perform significantly better on the BCT (obtain lower error scores) than the nondelusional group. Normal and delusional groups obtained significantly lower BCT error scores than the nondelusional group, even when differences in IQ scores were statistically partialled out. The two schizophrenic groups also differed significantly on BCT error scores with the delusional group performing better than the nondelusional group

Comparison of Experimental and Analytical Performance for Contoured Endwall Stators

Comparisons between predicted and experimental stator losses showed that the analysis was able to predict the change in stator loss when contoured endwalls with highly three dimensional passage geometry were used. The level of loss was predicted to within 75 percent of that measured. The predicted loss was due only to profile loss and boundary layer growth on the endwalls. The 25 percent difference was approximately 0.015 at design pressure ratio. The analysis was shown to predict the trend in stator flow angle, even for small stator geometries

Analytical and experimental investigation of stator endwall countouring in a small axial-flow turbine

An experimental and analytical investigation was conducted to determine the effect of stator endwall contouring on turbine stage performance. In this investigation three stator configurations were evaluated using a common rotor. The three stator configurations were a cylindrical endwall design and two contoured endwall designs, one having a S-shaped outer wall profile and the other having a conical-shaped outer wall profile. Experimental data were obtained over a range of equivalent speeds, total pressure ratios, and rotor tip clearances for each stator-rotor combination. Detailed analytical loss assessments were conducted to aid in the determination of the contouring effect on turbine performance

An AdS/QCD holographic wavefunction for the rho meson and diffractive rho meson electroproduction

We show that AdS/QCD generates predictions for the rate of diffractive rho meson electroproduction that are in agreement with data collected at the HERA electron-proton collider.Comment: 9 pages, 4 figures. Figure 3 added to illustrate that the AdS/QCD prediction is impressive. Accepted for publication in Physical Review Letter