methods for their minimization. The general objective is to develop criteria which can be used to design high performance supersonic and hypersonic aircraft which will generate low sonic boom pressures on the ground in the vicinity of the flight path. To accomplish this general objective, specific objectives which are being pursued at present are as follows: (1) To evolve and/or extend available analytical methods for determining the pressure field around aircraft of arbitrary shape. (2) To experimentally screen various promising configurations for minimum boom (based on present analytical technology). (3) To develop improved analytical methods for optimizing aircraft configurations for minimum sonic boom. At Ames, an attempt is being made to adapt computer graphics principles to three-dimensional flow field analysis and to develop an improved computer program for calculating supersonic flow fields about arbitrary aircraft configurations. Both these approaches could contribute to new techniques for modifying and improving the boom pressure signature in the far field (on the ground). At Langley, effort continues on similar improvement of prediction techniques, minimization concepts, better understanding of high supersonic shock-wave phenomena, and statistical analysis of flight test data. The recent work on the source of the sonic boom has resulted in the determination of optimum equivalent bodies of revolution that minimize the overpressure, shock pressure rise rate, and impulse for given weight, length, Mach number and altitude of operation. Progress is being made on the problem of determining how practical aircraft can be designed to provide values approaching these optimums. The R & D funding for contracts for research on the source of sonic boom for the NASA centers involved is as follows: (Details of these contracts appear in the appendix.) [In thousands of dollars) A broad program of investigation of the effects of atmospheric nonuniformities, winds, turbulence, etc., on sonic boom wave forms and also on means of producing a realistic and repeatable sonic boom environment for test purposes is underway at the Ames Research Center, the Langley Research Center, and under contract. At the Ames Research Center work is underway on the physics of shock coalescence as related to the sonic boom. The principal activity at the Langley Research Center is the modification of boom prediction techniques to verify calculation procedures and to incorporate recently developed propagation methods. Experimental flight test data is being correlated with sonic boom prediction methods to evaluate a recently developed propagation method. The most significant activity has been the recent program conducted at Jackass Flats, Nevada, under Langley Research Center direction during which sonic boom pressure signatures associated with aircraft operations at or near the threshold Mach number were determined by flight tests. The resulting data are being correlated with aircraft operations, meteorological conditions and theory for the purpose of determining the feasibility, from the boom standpoint, of operating supersonic aircraft in the low Mach number range. The pressure field at the extremities of the shock wave was obtained. The results provided a physical description of the depth and width of the focus region near the shock extremity. The behavior of the shock wave near the ex tremity was found to be sensitive to winds, turbulence and other atmospheric conditions. It was found that the "cutoff" Mach number is quite predictable if weather information is known. The R & D funding for contracts for research on the propagation of sonic booms for the NASA centers involved is as follows: (Details of these contracts appear in the appendix.) [In thousands of dollars] Langley Research Center. Total. Langley Research Center.. Contracts In-house R. & D. funding...... Contract R. & D. funding: Fiscal year 50 157 207 SONIC BOOM RECEPTOR RESEARCH The sonic boom affects both people and structures, and research is underway to understand these effects, to determine possible deleterious effects, and to develop efficient methods of protecting both people and structures from such effects. Sonic-boom source.. Subtotal, contracts..... Total NASA sonic-boom research R. & D. funding.. Total NASA R. & P.M. funding.... Total R. & D. and R. & P.M. funding... Work is underway both at the Langley Research Center and under contract on the response of representative building elements and assemblies to sonic booms. The R & D funding for contracts for research on the effects of sonic boom and its receptors (people and structures) for the NASA centers involved is as follows: (Details of these contracts appear in the appendix.) [In thousands of dollars] 120 Fiscal year 1971 Contracts Fiscal year 1970 Fiscal year 1971 SUMMARY OF NASA SONIC BOOM RESEARCH The resources (funding and professional manpower) required to carry out the program just described are given in the following tables. The funding is included in the Research and Development and Research and Program Management appropriations. The R&D dollars are spent in-house for purchase of test equipment and instrumentation and for research contracts. 100 10 134 244 Fiscal years 206 125 207 120 (452) 658 819 1,477 162 1971 363 178 244 162 (584) 947 735 1,682 Contractor and contract number APPENDIX NASA SONIC BOOM RESEARCH GRANTS AND CONTRACTS Langley Research Center [Dollars in thousands] Source research: Aerospace Corp., Los Angeles, Calif. (NAS1-10051). The purpose of this study is to determine if the release of large quantities This study attempts to extend the scattering theory of Crow by use of a A theory is being investigated which relates spikes on boom signatures Studies have just gotten underway to examine in detail the sonic boom focus phenomena. General American Transportation Corp., Niles, III. (NAS1-9252). Receptor research: Stanford Research Institute, Menlo Park, Calif. (NAS1-10528). Tests subjects will be evaluated by motor performance testing while performing under varied acoustic background including aircraft noise and simulated sonic booms. In addition, the effects of the same noises on the sleep of subjects will be studied in a specially designed sleep test room. General Applied Science Laboratory, Inc., Westbury, N.Y. (NAS1-9594). The principal direction of these studies is to determine the effects on structures of low-level repeated sonic boom exposures. Starting date A study of the validity of the heat field concept of sonic June 1970. boom alleviation. Propagation of sonic boom through turbulence. Title June 1969. Atmospheric effects on sohic boom pressure wave forms. September 1970. A numerical method to determine the pressure in a sonic December 1970. boom focus. Sonic boom simulation. Comprehensive study of the psycho-physiological reactions to sonic booms and their effects on sleep and startle. June 1969. February 1971. Acoustic response to various wall and room configurations November 1969. Massachusetts Institute of Technology, Cambridge, Mass. (NGL 22-009-135). The object of this investigation is to develop an analytical procedure for predicting the random response of platelike structures resting on soil and subject to seismic noise of aerodynamic origin. J. H. Wiggins Co., Palos Verde, Calif. (pending).. The purpose of this work is to further understanding of nonlinear effects on the generation of sonic booms by means of theoretical and experimental investigations. Response of building structures to environmental noise October 1970. of seismic, acoustics, and aerodynamic origin. Source research: Aerophysics Research Corp., Bellevue, Wash. (NAS2-4880). This study is directed toward the development of an analytical method for calculating supersonic flow-fields about arbitrary configurations. The method features a 3-dimensional distribution of singularities on the configuration. Propagation research: Aerophysics Research Corp., Bellevue, Wash. (pending). The purpose of this study is to extend sonic boom theory Into the hypersonic range. Total.. Theoretical study of window glass breakage with sonic boom loads. NASA HEADQUARTERS Investigation of nonlinearity, caustic and diffraction in wave propagation. Propagation research: Princeton University, Princeton, N.J. (NGL 31-001-119) A number of theoretical problems associated with sonic boom prediction will be investigation; specifically, the nonlinear behavior of an N-wave at a caustic, the extension of nonlinear theory to geometrical acoustics and so nic boom signatures within a shadow region. Aeronautical Research Institute of Sweden Bromma, Sweden (NGR 52-120-001)... Investigation of nonlinear effects on sonic boom genera- February 1971. tion. do. Development of hypersonic theory for the sonic boom. September 1969. (Following are statements submitted for the record in support of testimony given on the advanced research and technology program:) Hermann H. Kurzweg, Chief Scientist and Chairman of the Research Council, Office of Advanced Research and Technology Richard J. Wisniewski, Director, Advanced Concepts and Missions, National Aeronautics & Space Administration R. D. Ginter, Director, Technology Applications Office, Office of Advanced Research and Technology Gerald G. Kayten, Acting Director, STOL Technology Office, Office of Advanced Research and Technology Albert J. Evans, Director, Aerodynamics and Vehicle Systems, Office of Advanced Research and Technology Leo Fox, Director, Aeronautical Life Sciences Division, Office of Advanced Research & Technology Albert J. Evans, Acting Director, Aeronautical Propulsion, Office of Advanced Research & Technology George W. Cherry, Director of Aeronautical Operating Systems, Office of Advanced Research & Technology George C. Deutsch, Director, Materials and Structures Division, Office of Advanced Research and Technology Francis J. Sullivan, Director of Guidance, Control and Information Systems, Office of Advanced Research & Technology Gerald G. Kayten, Director, Supercritical Technology Office, Office of Advanced Research & Technology Adelbert O. Tischler, Director, Shuttle Technologies Office, Office of Advanced Research and Technology William H. Woodward, Director, Space Propulsion and Power, Office of Advanced Research & Technology H. Kurt Strass, Director, Safety and Operating Systems Office, Office of Advanced Research and Technology Fred J. DeMeritte, Director of Entry Technology, Office of Advanced Research & Technology Milton Klein, Manager, Space Nuclear Systems Office, National Aeronautics & Space Administration PREPARED STATEMENT OF DR. HERMANN H. KURZWEG, CHIEF SCIENTIST AND CHAIRMAN OF THE RESEARCH COUNCIL, OFFICE OF ADVANCED RESEARCH AND TECHNOLOGY, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION This statement is directed to the basic research activity under the cognizance of OART. It describes the nature, purpose, and value of this work and, in particular, how it is guided and coordinated by the newly created Research Council. The statement differs in nature from those of prior years because of changes in the management of Basic Research in OART; changes that permit the achievement of NASA's goals and objectives more effectively. Because the basic research effort is of paramount importance to NASA, certain steps have been taken to modify the organizational structure that enhances the basic research program and, at the same time, provides a greater infusion of the results of research into the OART applied and technology activities. First, the diverse work of the former Basic Research Program has been combined with the appropriate, allied OART Programs. Second, the position of Chief Scientist and a Research Council have been established in OART Headquarters to oversee the entire basic research activity. It is believed that with this new alignment a greater relevance both in accomplishing and in presenting the basic research can be fostered. In a mission oriented agency such as NASA, programs in basic research are directed toward accomplishing the missions and goals of the agency. It is OART's continuing endeavor to seek out the best possible means of implementing and reinforcing this concept. |