Includes product sampling procedures and techniques; and quality control. Includes structural element design and weight analysis; fatigue; and thermal stress. For applications see 05 For instrumentation see 35 Instrumentation and Photography. Includes specific energy conversion systems, e.g., fuel cells; global sources of energy; geophysical conversion; Includes atmospheric, noise, thermal, and water pollution. 68 Includes aeronomy; upper and lower atmosphere studies; ionospheric and magnetospheric physics; and Includes physiological factors; biological effects of radiation; and effects of weightlessness on man and animals. and Electrical Engineering. For precision time and time interval (PTTI) see 35 Instrumentation and Photography; for geophysics, astrophysics or solar physics see 46 Geophysics, 90 Astrophysics, or 92 Solar Physics. Includes sound generation, transmission, and attenuation. For noise pollution see 45 Environment Pollution. Includes atomic structure, electron properties, and molecular spectra. arts; and micrography. For computer documentation see 61 Computer Programming and Software. VOLUME 29 NUMBER 1 / JANUARY 8, 1991 Scientific and Technical Aerospace Reports A Semimonthly Publication of the National Aeronautics and Space Administration 01 AERONAUTICS (GENERAL) N91-10001# Office of the Under Secretary of Defense (Acquisitions), Washington, DC. DOD RESPONSIBILITIES ON FEDERAL AVIATION AND R. Nakamura 22 Jun. 1989 9 p (PB90-218827; DOD-D-5030.19) Avail: NTIS HC/MF A02 CSCL 01B The directive reissues Department of Defense (DoD) Directive 5030.19 and supersedes DoD Directive 5030.17. It updates DoD policy and procedures to address peacetime, wartime, and emergency relationships between DoD, DOT, FAA, and other government agencies. The DoD organizational structure is described for interface with the DoT, FAA, and other agencies on air traffic control and airspace matters, NAS matters, joint system acquisitions, and oversight of airlift service provided to the DoD by civil air carriers. DoD policy and planning guidance is provided for comprehensive DoD airspace planning and the relationships between the DoD, DOT, FAA, other government agencies, state governments, and civil communities. Author N91-10002* National Aeronautics and Space Administration, AERONAUTICAL ENGINEERING: A CONTINUING (NASA-SP-7037(256); NAS 1.21:7037(256)) Avail: NTIS HC A07; NTIS standing order as PB90-914100, $11.50 domestic, $23.00 foreign CSCL 01B This bibliography lists 426 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics. 02 AERODYNAMICS Author Includes aerodynamics of bodies, combinations, wings, rotors, and control surfaces; and internal flow in ducts and turbomachinery. For related information see also 34 Fluid Mechanics and Heat Transfer. N91-10003 National Aerospace Lab., Tokyo (Japan). CHARACTERISTICS OF PIPING INTERFERENCE ELIMINATION UNIT USED IN THE HIGH-SPEED WIND TUNNEL TEST OF ASUKA SEVEN PERCENT SEMI-BORN PROTOTYPE [ASUKA NANA PASENTO HANSETSU MOKEI NO KOUSOKU FUUDOU SHIKEN NI MOCHIITAHAIKAN KANSHOU JOKYO SOUCHI NO TOKUSEI NI TSUITE] Nobuyuki Hosoe, Toshio Karasawa, Keisuke Asai, Syouji Suenaga, Yo Koike, Hirokazu Suzuki, Masayoshi Nakamura, and Susumu Mitsubori Jun. 1988 17 p In JAPANESE (NAL-TM-588; ISSN-0452-2982; JTN-90-80015) Avail: NTIS HC/MF A03 In the high-speed aerodynamic test using a seven percent semiborne model for the low-noise STOL test aircraft, two TPS (Turbine Powered Simulators) were mounted for use in order to simulate the drive of an actual aircraft. In order to suppress the influence of the piping for supplying compressed air to the TPS measurement of air power by a balance of an external mount type (six percent balance), a unit for eliminating the influence of the piping was manufactured by way of trial. Factors which influence the piping measurement of air power are as follows: effect of air pressure in the piping, influence by the twisting and warping of the piping as a result of a change in the stance of the model, influence by the division of air power between the balance and the piping due rigidity of the piping itself, influence of thermal elongation and contraction of the piping, influence of the flow of compressed air in the piping. To minimize these influences, use was made of a combination of Zimbal bellow, high-pressure rubber hose, and apherical joint was made for eliminating the influence of the piping on an experimental basis which was checked for effect by conducting a wind-tunnel test with and without introduction of air. NASDA N91-10004# Arnold Engineering Development Center, Arnold Air Force Station, TN. USER'S GUIDE TO CUNIFLOW Final Report, 1 Oct. 1981 - 30 Sep. 1988 James T. Curtis Apr. 1989 118 p Prepared in cooperation with Calspan Field Services, Inc., Arnold AFS, TN (AD-A207606; AEDC-TR-88-31) Avail: NTIS HC/MF A06 CSCL 01/2 CUNIFLOW is a fast, mature code for calculating the hypersonic flow of an inviscid reacting gas over an axisymmetric or planar body. The thermochemical model allows for the finite-rate chemical relaxation of an arbitrary mixture of perfect gases and the coupling of dissociation with nonequilibrium vibrational relaxation. Options for calculating the effects of radiant energy loss, of nonuniform free-stream conditions, and of boundary-layer displacement are available. A particular advantage of the code, in addition to its speed, is that it can often be made to complete calculation for near-equilibrium situations where other reacting flow codes encounter difficulties. The thermophysical models and the computational methods embodied in the code are summarized and instructions for inputting a problem and interpreting the output are provided. The computational time for a standard configuration is plotted as a function of centerline velocity for various values of the binary scaling parameter. Author N91-10005# Ballistic Research Labs., Aberdeen Proving Ground, PREDICTION AND COMPARISON WITH MEASUREMENTS OF James E. Danberg, Asher Sigal, and Ilmars Celmins May 1989 12 p Prepared in cooperation with Technion-Israel Inst. of Tech., Haifa (DA Proj. 1L1-62618-AH-80) (AD-A208099; BRL-MR-3752) Avail: NTIS HC/MF A03 CSCL 01/1 A systematic study of a number of flare-stabilized projectile geometries has been undertaken at the U.S. Army Ballistic Research Laboratory (BRL). Ten projectile configurations having identical forebodies and a variety of flares were tested in the BRL Aerodynamics Ballistic Range and the results compared to numerical computations based on two design codes and a Parabolized Navier-Stokes (PNS) code. The design codes, in general, gave good results. The PNS code complemented these results by providing more details on the development of the aerodynamic forces. The results show the drag and stability trade-offs involved for the different configurations. This information can be used to tailor the flare geometry to meet future mission requirements. Author N91-10006 Georgia Inst. of Tech., Atlanta. Avail: Univ. Microfilms Order No. DA9014871 A finite-state inflow model is developed that models the three-dimensional rotor inflow in hover, axial flight, or forward flight. The basis of the model is an acceleration potential with a skewed cylindrical wake. The scope and objectives of the present research revolve around the development of this theoretical basis into a useful research and design tool for hover and axial flight. First, we establish the harmonic and radial convergence characteristics of the model. One-bladed and four-bladed rotors are used in this analysis. Second, this model is coupled with elastic-blade flap equations in hover and also in axial flight in order to determine its effect on aerodynamic damping. Third, the role of periodic coefficients in the dynamic response is investigated. A multi-blade coordinate transformation technique is used to transform the flap equations from the rotating to the nonrotating system. Similarly, the induced flow can be written in either the rotating or the nonrotating system. The effect of periodic coefficients is dependent upon which set of blade equations is coupled with which set of inflow equations. Fourth, we related the generalized forces in the inflow equations to the generalized forces already being used for structural response by constructing intermediate transformation matrices. Results obtained from these tasks show that the present model converges with 3 shape functions per harmonic and has high computational efficiency as compared to unsteady vortex-filament models. More importantly, results indicate that unsteady inflow is an important physical phenomenon that changes the qualitative nature of rotor dynamics in hover and in axial flight. Dissert. Abstr. N91-10007*# National Aeronautics and Space Administration. TRANSONIC FLOW ANALYSIS FOR ROTORS. PART 3: I-Chung Chang Jun. 1990 23 p (NASA-TP-2375; A-86374-Pt-3; NAS 1.60:2375) Avail: NTIS HC/MF A03 CSCL 01A A new method is presented for calculating the quasi-steady transonic flow over a lifting or non-lifting rotor blade in both hover and forward flight by using Euler equations. The approach is to solve Euler equations in a rotor-fixed frame of reference using a finite volume method. A computer program was developed and was then verified by comparison with wind-tunnel data. In all cases considered, good agreement was found with published experimental data. Author N91-10008# Los Alamos National Lab., NM. B. A. Wagner 1990 10 p (DE90-014903; LA-UR-90-2437; CONF-9010154-1) Avail: NTIS HC/MF A03 The flow field over a class of 2-D lifting surfaces is examined from the viewpoint of inviscid, hypersonic small disturbance theory = (HSDT). It is well known that a flow field in which the shock shape S(x) is similar to the body shape F(x) is only possible for F(x) = x sup k and the freestream Mach number M sub infinity infinity. This self-similar flow has been studied for several decades as it represents one of the few existing exact solutions of the equations of HSDT. Detailed discussions are found for example in papers by Cole, Mirels, Chernyi and Gersten and Nicolai but they are limited to convex body shapes, that is, k less than or = 1. The only study of concave body shapes was attempted by Sullivan where only special cases were considered. The method used here shows that similarity also exists for concave shapes and a complete solution of the flow field for any k greater than 2/3 is given. The effect of varying k on C sub L sup 3/2 C sub D is then determined and an optimum shape is found. Furthermore, a wider class of lifting surfaces is constructed using the streamlines of the basic flow field and analysed with respect to the effect on C sub L sup 3/2 C sub D. DOE N91-10009*# Institute for Computer Applications in Science and Engineering, Hampton, VA. BOUNDARY-LAYER RECEPTIVITY DUE TO A WALL SUCTION AND CONTROL OF TOLLMIEN-SCHLICHTING WAVES Final Report R. J. Bodonyi and P. W. Duck (Manchester Univ., England) Sep. 1990 34 p Submitted for publication (Contract NAS1-18605) (NASA-CR-182103; NAS 1.26:182103; ICASE-90-62) Avail: NTIS HC/MF A03 CSCL 01A A numerical study of the generation of Tollmien-Schlichting (T-S) waves due to the interaction between a small free-stream disturbance and a small localized suction slot on an otherwise flat surface was carried out using finite difference methods. The nonlinear steady flow is of the viscous-inviscid interactive type while the unsteady disturbed flow is assumed to be governed by the Navier-Stokes equations linearized about this flow. Numerical solutions illustrate the growth or decay of T-S waves generated by the interaction between the free-stream disturbance and the suction slot, depending on the value of the scaled Strouhal number. An important result of this receptivity problem is the numerical determination of the amplitude of the T-S waves and the demonstration of the possible active control of the growth of T-S Author waves. N91-10010*# Institute for Computer Applications in Science and Engineering, Hampton, VA. TURBULENT FLOW CALCULATIONS USING UNSTRUCTURED AND ADAPTIVE MESHES Final Report Dimitri J. Mavriplis Sep. 1990 32 p Submitted for publication (Contract NAS1-18605) (NASA-CR-182102; NAS 1.26:182102; ICASE-90-61) Avail: NTIS HC/MF A03 CSCL 01A A method of efficiently computing turbulent compressible flow over complex two dimensional configurations is presented. The method makes use of fully unstructured meshes throughout the entire flow-field, thus enabling the treatment of arbitrarily complex geometries and the use of adaptive meshing techniques throughout both viscous and inviscid regions of flow-field. Mesh generation is based on a locally mapped Delaunay technique in order to generate unstructured meshes with highly-stretched elements in the viscous regions. The flow equations are discretized using a finite element Navier-Stokes solver, and rapid convergence to steady-state is achieved using an unstructured multigrid algorithm. Turbulence modeling is performed using an inexpensive algebraic model, implemented for use on unstructured and adaptive meshes. Compressible turbulent flow solutions about multiple-element airfoil geometries are computed and compared with experimental data. Author |