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Following a proof-of-principle demonstration of Planar Laser-Induced Fluorescence (PLIF) in the AEDC Impulse Facility in FY93, a set of four PLIF images was obtained during FY94 runs of the facility. The images were obtained away from the nose region of a spherically blunt cone, using excitation of nitric oxide in the flow. Two laser sheet geometries were employed and two excitation wavelengths were used. A procedure was developed whereby calibration images allow the remapping of the PLIF images to test article coordinates. Using this technique, it was shown that the bow shock positions determined by PLIF agree well with the shock positions measured using schlieren photography. More importantly, the set of PLIF images constitutes an initial database against which Computational Fluid Dynamics calculations of high enthalpy flows can be compared. Initial results of such a comparison, obtained through Computational Flow Imaging, are reported. Recommendations are given for future PLIF applications at the Impulse Facility. (MM), Orginal contains color plates: All DTIC/NTIS reproductions will be in black and white.

A test was conducted to obtain nonintrusive measurements in the flow field about an axisymmetric nozzle afterbody with a cold, underexpanded jet, M sub j=1.563, in a parallel free stream, M sub alpha = 0.6. Reynolds shear stress and two components of mean velocity and turbulence intensity were measured using a two-color Bragg-diffracted laser Doppler velocimeter. Additional experimental data include the afterbody surface pressure distribution and laser vapor screen flow visualization of the jet plume. A multiple seeding technique was used to investigate the bimodal velocity probability distributions observed in the jet mixing region. (Author), Prepared in cooperation with Calspan Field Services, Inc., Arnold AFS, TN. AEDC Div.

A test was conducted in the Arnold Engineering Development Center (AEDC) Aerodynamic Wind Tunnel (1T) of the Propulsion Wind Tunnel Facility (PWT) to measure the flow fields about several wing/pylon/store configurations. Test models included a wall-mounted swept wing, five-percent MK-83 and M-117 stores, and swept and unswept pylons. Flow-field velocity measurements, made by using a three-component laser velocimeter, are presented. (Author), Prepared in cooperation with ARO, Inc., Tullahoma, TN.

Larger optical windows for access to the model flow field in the Arnold Engineering Development Center (AEDC) transonic wind tunnels will be required for optimum utilization of the laser velocimeter (LV). A combined analytical and experimental investigation was performed to assess the effects of such windows upon the performance of the perforated walls. The experimental results from the Aerodynamic Wind Tunnel (1T) indicate that although the wall interference characteristics of some window configurations approach the standard porous wall, none of the configurations tested exhibited adequate wave cancellation for all Mach numbers from M at infinity = 1.0 through 1.4. A variable porosity wall arrangement is described which appears to be capable of providing acceptable optical access without adversely affecting the tunnel flow field. (Author), Prepared in cooperation with ARO, Inc., Tullahoma, TN.

A vortex lattice method has been applied to the problem of predicting the interference induced by ventilated wind tunnel walls. The formulations of both perforated and slotted wall boundaries using the vortex lattice method are presented. Wall interference effects on a single lifting line vortex for several basic wind tunnel test section configurations are compared with other theoretical results. Use of the vortex lattice method to calculate the aerodynamic characteristics of a lifting model too complex for exact analytical treatment is discussed. The surface pressure distribution on a combined wing and tail representation computed for a free stream is presented as well as those for both closed and slotted test sections to illustrate the capability of the technique. (Author), Prepared in cooperation with ARO, Inc., Tullahoma, TN.

A test was conducted in the AEDC Aerodynamic Wind Tunnel (1T) of the Propulsion Wind Tunnel Facility (PWT) to measure the flow fields about 5-percent models of several wing/store configurations. Test models included a wall-mounted swept wing and MK-83 and M-117 stores. Flow-field velocity measurements, made using a 2-component laser velocimeter, are presented together with model surface pressures and shadowgraphs. (Author), Prepared in cooperation with ARO, Inc., Tullahoma, TN.

An investigation is described for providing detailed nonintrusive laser Doppler velocimeter (LDV) flow field measurements for several nozzle-afterbody configurations with cold nitrogen exhaust jets. Pertinent information about the test facility and associated instrumentation system is given. The test articles, including one with a 15 deg. boattail afterbody and two having blunt bases, are described. The two-color, two-component LDV optical package and data acquisition; system used for the flow field measurements are discussed. The effects of particle dynamics upon the LDV measurement uncertainty are reviewed. Recent work directed toward predicting and correcting for such effects is explained. Fluorescent seeding was used in conjunction with multiple seeding techniques to gain a more complete understanding of the complex flow interactions in the model base region. Test results are summarized and selected data are presented and discussed., This article is from 'Wind Tunnels and Testing Techniques,' AD-A143 674, p27-1-27-14.

A study was conducted to develop an analytical model for the investigation of flow fields about intermediate disc loading lift devices for VTOL applications. Classical vortex-lattice theory was used in conjunction with experimental data for representing a free propeller in a crossflow. The jet phenomena to be simulated by the method are discussed. A number of previous attempts at vortex-lattice modeling are presented. Analytical stream lines and field vectors are compared with available experimental data. The results are evaluated and recommendations are made for further model development., Prepared in cooperation with ARO, Inc., Tullahoma, TN. Rept. no. ARO-OMD-TR-72-98.