Ballistic Research Laboratory Research Articles

Acoustic and Photographic Studies of Solid Rocket-Propellant Combustion Instability

Solid-propellant combustion-instability studies at the Ballistic Research Laboratories have been concerned with three main areas: namely, (1) a photographic investigation of aluminum-additive burning phenomena, (2) acoustic admittance measurements of the burning surface, and (3) measurement of acoustic erosivity effects on the burning rate. The first program, which was recently completed, was a photographic study of possible aluminum-additive contributions to low-frequency instability. In this investigation, propellant slabs were burned in a windowed and vented chamber. A rotating slotted wheel was pulled over the vent in some instances to provide pressure waves normal to the burning surface. A short film is shown of some of the test runs. The second program is concerned with the measurement of the acoustic admittance of a burning-propellant surface, using a resonant-tube technique. This work closely parallels that at the Naval Ordnance Test Station and the University of Utah. Recent studies have been aimed at evaluating experimentally some of the sources of acoustic losses in this system. The third program is a study of the dependence of the burning rate of a propellant on the frequency and magnitude of the fluctuating gas velocity parallel to the transpiring surface. A description of the apparatus and a summary of recent results are given.

Flexural Vibration of Shallow Orthotropic Spherical Shells

The paper presents the theoretical development of the equations of motion for the flexural vibrations of a shallow spherical shell of orthotropic material. For symmetrical vibrations, the motion is described by two ordinary sixth-order differential equations with variable coefficients. Factorization of the sixth-order operators into second-order operators is discussed, and the details of solution are worked out for the case in which the equations are reduced to those for the isotropic shell. It is shown that equations for the latter case agree exactly with those derived previously by Reissner [Eric Reissner, “On Vibrations of Shallow Spherical Shells,” J. Appl. Phys. 17, 1038–1042 (1946)]. A table of calculated frequencies is given along with some experimental results for steel shells. (This investigation was conducted under Contract No. DA-30-115-509-ORD-912, Department of Army Ordnance Corps, Ballistic Research Laboratory, Aberdeen, Maryland.)

Flow Over a Cone at an Angle of Attack for High Mach Number

Translated from Izvestiia Akademii Nauk SSSR, Otdel. Tekh. Nauk {Bulletin of the Academy of Sciences USSR, Div. Tech. Sci.), 1958, no. 7. Translated by B. G. Karpov under the auspices of U. S. Army Ordnance, Ballistic Research Laboratories, Aberdeen Proving Ground, Md. This translation was supplied to the American Rocket Society by C. H. Murphy, Chief, Free Flight Aerodynamics Branch, Ballistic Research Laboratories. A. L. GONOR

Preliminary Orbit Determination of a Nontransmitting Satellite Using the DOPLOC Tracking System

A method is presented for predicting a preliminary orbit of a passive (nontransmitting) satellite, using tracking data collected during one passage of the satellite by a tracking system consisting of only one transmitter and one receiver of the DOPLOC network. Equations are derived which relate passive satellite Doppler tracking data to range, speed, and time parameters at closest approach. These determine an ellipsoid whose foci are the transmitter and receiver stations. The satellite lies on this ellipsoid, and its trajectory is tangent to the surface. This ellipsoid can be completely determined without using any angle information. The satellite position and velocity components at closest approach are then calculated on a digital computer using Doppler and limited angle information provided by the DOPLOC tracking system. Preliminary orbits determined in this way agree favorably with the refined orbits of Ballistic Research Laboratories and Space Track.

Upper Atmospheric Research at the Ballistic Research Laboratories

A summary of BRL activities in upper atmosphere research is presented. From a quite modest beginning, the International Geophysical Year gave impetus to a considerable program. Results of electron content measurements in the ionosphere employing rocket borne transmitters are reported. Studies of the water vapor content of the atmosphere and the optical properties of the earth's horizon using balloon borne and rocket borne instrumentation are being made. Some comments on the use of catalytic surfaces to study recombination rates in the atmosphere are given.

Earth's main magnetic field to 152 kilometers above Fort Churchill

In conjunction with the IGY rocket program of the Ballistic Research Laboratories, proton precession magnetometers [Heppner, 1958] have been flown in Nike-Cajun rockets at Fort Churchill, Canada, under magnetically quiet and disturbed conditions in the daytime. This letter is a report on the quiet-field measurements. Rocket instrumentation included the precession magnetometers, DOVAP tracking and telemetry system [Berning, 1954, pp. 70-72], flux-gate aspect magnetometers, and a transistor-switch commutator. Pertinent data concerning Fort Churchill and the rocket flights areFort Churchill dataGeographic latitude 58.8°NGeographic longitude 94.2°WMagnetic latitude 69°Dip 84°IGY-OB6.16 rocket flight dataFiring date Nov. 30, 1958Firing time 1627 CST (2227 UT)Peak altitude 152 kmPeak time 190 secRange to impact 48 kmImpact azimuth 37° E of NSpin rate 0.4 rps

Advanced Education and Academic Research in Aeronautics

The Forty-Fifth Wilbur Wright Memorial Lecture, “Advanced Education and Academic Research in Aeronautics” was given before the Society by Dr. Clark B. Millikan, Hon.F.I.A.S., F.R.Ae.S., on 13th September 1957, at the Institution of Civil Engineers, Great George St., London, before a large and distinguished audience which included H.R.H. The Prince of the Netherlands and a number of the Americans who had attended the Sixth Anglo-American Aeronautical Conference. Sir George Edwards, C.B.E., B.Sc, F.R.Ae.S., President of the Society, presided. As has now become customary the principal awards of the Society awarded by the Council for the year were presented before the lecture (see July and October 1957 Journals). This year they included Honorary Fellowship of the Society which was accepted by His Royal Highness, The Prince of the Netherlands.Introducing the Lecturer, Sir George Edwards said:–Dr. Millikan was born in Chicago in 1903, he graduated from Yale University in 1924 with the degree of Ph.B. and received a Ph.D. degree in physics and mathematics at the California Institute of Technology in 1928. In that year he was appointed Assistant Professor at the California Institute, in 1934 he became Assistant Professor, and since 1940 he has been a full Professor in the Aeronautics Department. He was a member of the Executive Committee of the Institute from 1945 to 1947 and was appointed Director of the Guggenheim Aeronautical Laboratory in 1949. He has been Director of Wind Tunnel Testing at the California Institute since 1935, and Director of the Southern California Cooperative Wind Tunnel since it began operations in 1945. He is Chairman of the C.I.T. Trustees Jet Propulsion Laboratory Committee.A Fellow of the Royal Aeronautical Society and an Honorary Fellow of the Institute of the Aeronautical Sciences, of which he was President in 1937, he is also a member of a number of other Societies. In 1948 the British Government awarded him the King's Medal for Service in the Cause of Freedom, and in 1949 he received the United States Medal for Merit.Dr. Millikan is currently serving as Chairman of the Scientific Advisory Committee to the U.S. Secretary of Defense and as Chairman of the Aircraft and Guided Missiles Panel of the U.S.A.F. Scientific Advisory Board. He is also a member of the Army's Ballistic Research Laboratories' Scientific Advisory Committee, Chairman of the Sub- Committee on Fluid Mechanics and a member of the Aerodynamics Committee of the National Advisory Committee for Aeronautics.

On the theory of replacement of machinery with a random failure time

Naval Research Logistics QuarterlyVolume 3, Issue 4 p. 279-293 Article On the theory of replacement of machinery with a random failure time† George H. Weiss, George H. Weiss U. S. Naval Ordnance Laboratory, White Oak, Silver Spring, MarylandSearch for more papers by this author George H. Weiss, George H. Weiss U. S. Naval Ordnance Laboratory, White Oak, Silver Spring, MarylandSearch for more papers by this author First published: December 1956 https://doi.org/10.1002/nav.3800030406Citations: 16 † This work was performed while the author was employed at the Ballistic Research Laboratories, Aberdeen Proving Ground, Aberdeen, Maryland. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume3, Issue4December 1956Pages 279-293 RelatedInformation

Some problems solvable on computing machines

Communications on Pure and Applied MathematicsVolume 7, Issue 1 p. 149-158 Article Some problems solvable on computing machines Mark Lotkin, Mark Lotkin Ballistic Research Laboratories, AberdeenSearch for more papers by this author Mark Lotkin, Mark Lotkin Ballistic Research Laboratories, AberdeenSearch for more papers by this author First published: February 1954 https://doi.org/10.1002/cpa.3160070111AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume7, Issue1February 1954Pages 149-158 RelatedInformation

The BRL-NGF Cinetheodolite

A number of incomplete Askania cinetheodolites are being extensively rehabilitated and modified under a joint program of the Navy Bureau of Ordnance and the Army Ordnance Ballistic Research Laboratories. New features include improved bearings, data circles, complete replacement of all mount components except carriage castings, a Mitchell high-speed camera movement operating synchronously at 16, 32 or 64 frames/sec, 500-ft magazines, and telescopic optical systems of 60-, 96-, 144- and 180-in. focal lengths.

A New Integration Procedure

Journal of Mathematics and PhysicsVolume 32, Issue 1-4 p. 171-179 Article A New Integration Procedure M. Lotkin, M. Lotkin Ballistic Research Laboratories Aberdeen Proving GroundSearch for more papers by this author M. Lotkin, M. Lotkin Ballistic Research Laboratories Aberdeen Proving GroundSearch for more papers by this author First published: April 1953 https://doi.org/10.1002/sapm1953321171Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume32, Issue1-4April 1953Pages 171-179 RelatedInformation

A New Integrating Procedure of High Accuracy

Journal of Mathematics and PhysicsVolume 31, Issue 1-4 p. 29-34 Article A New Integrating Procedure of High Accuracy Mark Lotkin, Mark Lotkin Ballistic Research Laboratories Aberdeen Proving GroundSearch for more papers by this author Mark Lotkin, Mark Lotkin Ballistic Research Laboratories Aberdeen Proving GroundSearch for more papers by this author First published: April 1952 https://doi.org/10.1002/sapm195231129Citations: 6AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume31, Issue1-4April 1952Pages 29-34 RelatedInformation

Sytematization of Tube Surveillance in Large-Scale Computers

Operation of the ENIAC (electronic numerical integrator and calculator), a high-speed electronic computing machine, at the Ballistic Research Laboratories of Aberdeen Proving Ground, has shown that 90 per cent of the service interruptions are caused by vacuum-tube failures. At the beginning of 1950 a tube surveillance program was initiated in which all pertinent data concerning each tube in the system are recorded on punched cards. This paper describes the manner in which faulty vacuum tubes are detected and replaced, and gives the specifications used in testing the tubes and the manner in which the tube history is gathered. Preliminary results, using data collected during the first five months of 1950, are given.

International Business Machines for spectroscopic absolute-magnitude reductions and results for 500 A5-G stars.

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS International Business Machines for spectroscopic absolute-magnitude reductions and results for 500 A5-G stars. Hoffleit, Dorrit Abstract In resumption of the war-interrupted Harvard program for the determination of spectroscopic absolute magnitudes of bright southern stars, provisional results have now been obtained for approximately 500 A5-G2 stars, most of them 5-7 visual mag. and south of 200. The spectra were obtained at the Harvard Southern Station with the I ~-inch Boyden refractor and an ob- jective prism giving a dispersion at H~ of 45 A!mm. The estimates of line intensiti~s were carried out at Harvard, two-thirds of them prior to 1942. The reductions were performed on the International Business Machine equipment of the Ballistic Research Laboratories, Aberdeen Proving Ground, through the generous perm1s- sion of Col~nel Leslie E. Simon. The advantages of punch cards in the reduction of data for "normal" stars are discussed. The spectroscopic absolute magnitudes are compared with absolute magnitudes computed from trigonometric parallaxes, reduced proper motions, and spectroscopic results obtained at other observatories. The relative scale and zero- point errors of the Harvard reductions for the main sequence stars are within the natural uncertainties of the various systems. A total dispersion in absolute magnitude of +0.7-0.8 is found of which +0.5 mag. is apparent observational error. This leaves +0.5 mag. as the indicated dispersion of the true absolute magnitudes, a result not inconsistent with published results from various statistical investigations. The list of stars contains numerous peculiar objects, namely: 6 "Strontium stars" I "Chromium Europium star" 39 "Metallic-line stars" 9 Cepheid variables I Star with probable variable spectrum, HR 7055 23 Other supergiants. The Harvard absolute magnitudes for the supergiant stars are poorly determined. This is primarily because these stars were not separated from the others in the automatic machine reductions, and it is well known that all the criteria for the run of the stars are not applicable to supergiants. Also, too few data are available for an independent calibration of the supergiants. They are, however, included in the discussion in order to demonstrate the consequence of ignoring luminosity class before `calibrating supergiant luminosities. About 40 of the stars have "ambiguous" spectral classes. On the basis of Miss Cannon S Henry Draper criteria they are A stars while Mount Wilson's metallic-line criteria place them in the F groups. The absolute magnitudes estimated for both types indicate no definitive preference for either. Color data (Cape photographic magnitudes) indicate a slight preference for the F-types. On the other hand, in a comparison of Victoria (classified on the Draper system) and Mount Wilson spectral classes for northern stars, the colors of stars with discordant spectral classes appear to favor the earlier class. For 50 of the stars the Yale Bright Star Catalogue has listed variable radial velocities: 7 Cepheids, 17 possible binary stars, the rest undefined. For 30 of these more than one Harvard spectrum each was available. With the exception of the plates for one Cepheid, the plates showed no variations in line intensities beyond the differences attributable to diverse quality and exposure. The reduction and analysis of data such as those described require a large amount of sorting, listing, averaging and re-sorting of data. A moderately experienced operator would find I.B.M. equipment advantageous except in the analysis of those peculiar stars which are not, amenable to statistical methods. Harvard College Observatory, Cambridge, Mass. Publication: The Astronomical Journal Pub Date: 1948 DOI: 10.1086/106169 Bibcode: 1948AJ.....54S..39H full text sources ADS |

Some Ballistic Contributions to Aerodynamics

A systematic study of projectile aerodynamics has been made in the spark photography range of the Ballistic Research Laboratory, and the results on drag are now sufficiently complete to have general application to compressible flow problems. The performance of conical heads is analyzed by the first order theory and by the theory of Taylor and Maccoll, extended to additional cone angles. An empirical formula representing the variation of drag coefficient with Mach Number is presented. The quantity V 1 + KDM is shown to vary linearly with M at supersonic speeds for a wide variety of projectile shapes. Results on the length of boattailing are given. For a fixed boattail angle, it is shown that the drag coefficient decreases linearly with base area, tha t the side and base pressures are constant and independent of boattail length, and that their difference is portional to the slope of the linear function. The effects of banding, scale (size), interaction of head on base, and skin friction are discussed briefly. • Application is then made of these ballistic results to the design of a supersonic aircraft fuselage shape giving minimum drag, with a fixed body diameter and with the arbitrary choice of a conical head and conical boattail. A 50-in. diameter fuselage a t 50,000 ft. and a 20-mm. model at sea level are considered. I t is found that the design and performance of the two are similar, with the optimum head angle (semi vert ex) being near 4°. At a Mach Number of 1.5, base pressure and skin friction are nearly equal and account for over 85 per cent of the drag. As the Mach Number is increased to 5.0, the skin friction alone accounts for 75 per cent of the drag. The boattail is found to effect a saving of 23 per cent or more in drag, even at a Mach Number of 5.0. The power required for the 50-in. fuselage flying at a Mach Number of 1.5 is computed to 2.263 hp. a t 50,000 ft., which increases to the impractical figure of 21,243 hp. at sea level.

The Eniac, an Electronic Computing Machine

Introduction ENIAC (Electonic Numerical Integrator and Computor) is the name given to a large general-purpose caflinlating machine, operating by the counting of elctrical pulses by electronic counting circuits, which has recently been built at the Moore School of Electonic Engineering of the University of Pennsylwania, Philadelphia. It was devised by Dr. J. Prosper Eckert and Dr. John Mauchly, then of the Moore School, and was developed for the Ballistics Research Laboratory at Aberdeen Proving Ground, this development being sponsored by the U.S. War Department on the initiative of Colonel Paul 1ST. Gillon of the Office of the Chief of Ordnance; Dr. (then Capt.) Herman H. Goldstein was closely associated with the development of the machine as representative of the Ordnance Department at the Moore School. A short article on this machine has already appeared in Nature (April 20, p. 527). I have recently returned from a visit to the United States in the course of which I had the privilege of working with this machine, and this fuller account is based on this experience.