Hypersonic shock-heated flow parameters for velocities to 46,000 feet per second and altitudes to 323,000 feet
Real air hypersonic shock-heated flow parameters at high speeds and high altitudes
SHOCK HEATING↗
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Time Histories of Horizontal-tail Loads, Elevator Loads, and Deformations on a Jet-powered Bomber Airplane During Wind-up Turns at Approximately 15,000 Feet and 22,500 Feet
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Mcgowan, William A↗
Time histories of horizontal-tail loads and deformations on a jet-powered bomber airplane during wind-up turns at 15,000 feet and 22,500 feet
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Mcgowan, William A↗
Atmospheric Turbulence Measurements Obtained from Airplane Operations at Altitudes Between 20,000 and 75,000 Feet for Several Areas in the Northern Hemisphere
Measurements of clear-air turbulence by use of airplane-borne instrumentation have been obtained from NASA VGH recorders during research flights of Lockheed U-2 airplanes to altitudes of 75,000 feet over several areas of the Northern Hemisphere. An analysis of these data has indicated that for the higher altitudes (50,000 to 75,000 feet), turbulence is both less frequent and less severe than for the lower altitudes (20,000 to 50,000 feet). Turbulence appears to be present at the high altitudes (60,000 to 75,000 feet) less than 1 percent of the time. Moderately heavy turbulence appears to exist on occasion at altitudes of about 50,000 feet over Japan. As a consequence, the gust experience appears to be more severe for operations over Japan than for the other areas. Less than 50 percent of the turbulent areas exceeded 10 miles in length.
Coleman, Thomas L.↗
Combined Limb-Sparing Surgery and Radiation Therapy to Treat Sarcomas of the Hands and Feet: Long-Term Cancer Outcomes and Morbidity
Purpose: The purpose of this study was to investigate local control, survival outcomes, and complication rates of patients treated with limb-sparing surgery and radiation therapy (RT) for soft tissue sarcomas (STS) of the hands and feet. Methods and Materials: We reviewed the medical records of 85 consecutive patients treated for STS of the hands (n=38, 45%) and feet (n=47, 55%) between 1966 and 2012. The median age was 41 years (range, 10-82 years of age). Sixty-seven patients (79%) received postoperative RT after resection of their tumor (median dose, 60 Gy; range, 45-70 Gy). The remaining 18 patients (21%) were treated with preoperative RT followed by tumor resection (median dose, 50 Gy; range, 50-64 Gy). Results: Median follow-up was 140 months (range, 24-442 months). Five-year local control, overall survival, and disease-specific survival rates were 86%, 89%, and 89%, respectively. Positive or uncertain surgical margin status was the only factor adversely associated with local recurrence (19% vs 6% for negative margins, P=.046) but this lost significance on multivariate analysis when adjusting for RT dose ≥64 Gy. Of the 12 patients who had local relapses, 6 (50%) were salvaged, and only 2 of those required salvage amputation. Five patients had grade ≥3 late RT sequelae, with 2 patients (2%) having moderate limitations of limb function and 3 patients (4%) having severe limitations requiring procedures for skin ulceration. Conclusions: Limb-sparing surgery combined with RT provides excellent local control outcomes for sarcomas arising in the hands or feet. In patients who have local recurrence, salvage without amputation is possible. The excellent cancer control outcomes observed, considering the minimal impact on limb function, support use of combined modality, limb-sparing local therapy for STS arising in the hands or feet.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
EVIDENCE FOR ROTATIONAL MOTIONS IN THE FEET OF A QUIESCENT SOLAR PROMINENCE
We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent hedgerow prominence. The data show opposite Doppler shifts, {+-}6 km s{sup -1}, at the edges of the prominence feet. We argue that these shifts may be interpreted as prominence plasma rotating counterclockwise around the vertical axis to the solar surface as viewed from above. The evolution of the prominence seen in EUV images taken with the Solar Dynamics Observatory provided us with clues to interpret the results as swirling motions. Moreover, time-distance images taken far from the central wavelength show plasma structures moving parallel to the solar limb with velocities of about 10-15 km s{sup -1}. Finally, the shapes of the observed intensity profiles suggest the presence of, at least, two components at some locations at the edges of the prominence feet. One of them is typically Doppler shifted (up to {approx}20 km s{sup -1}) with respect to the other, thus suggesting the existence of supersonic counter-streaming flows along the line of sight.
79 ASTRONOMY AND ASTROPHYSICS↗
Airplane Measurements of Atmospheric Turbulence at Altitudes Between 20,000 and 55,000 Feet for Four Geographic Areas
Measurements of clear-air turbulence by use of airplane-borne instruments have been obtained from NACA VGH recorders during research flights of Lockheed U-2 airplanes at altitudes between 20,000 and 55,000 feet over Western United States, England and Western Europe, Turkey, and Japan. An analysis of these data has indicated that at the higher altitudes (40,000 to 55,000 feet) turbulence is both less frequent and less severe than at the lower altitudes (20,000 to 40,000 feet). Turbulence appears to be encountered at the high altitudes for only about 2 percent of the flight distance as compared with 5 percent or more at the lower altitudes. Moderately heavy turbulence exists on occasion at altitudes of about 50,000 feet over Japan and appears to be associated with the strong character of the jet stream in this area and also with a mountain-wave phenomenon.
Coleman, Thomas L.↗
A new characterization of the icing environment below 10,000 feet AGL from 7,000 miles of measurements in supercooled clouds
A growing requirement over the past decade for a new assessment of aircraft icing conditions in wintertime clouds at altitudes up to about 10,000 feet is discussed. The requirement was documented in past workshops and comes primarily from the helicopter community which wants ice-protected rotorcraft to meet increasing demands for all-weather operations. Currently, only a few of the larger helicopters are equipped with certification of ice-protection devices. This is because the current FAA criteria for design and certification of ice-protection equipment results in power and payload penalties that smaller rotorcraft cannot tolerate. The FAA criteria were actually designed for large, transport-category aircraft capable of flying to 20,000 feet or more. For this reason, there have been concerns that the current criteria may be too severe for low-performance aircraft, such as helicopters, which generally operate at altitudes below 10,000 feet.
Jeck, R. K.↗
Ground Measurements of Airplane Shock-Wave Noise at Mach Numbers to 2.0 and at Altitudes to 60,000 Feet
The intensity of shock-wave noise at the ground resulting from flights at Mach numbers to 2.0 and altitudes to 60,000 feet was measured. Meagurements near the ground track for flights of a supersonic fighter and one flight of a supersonic bomber are presented. Level cruising flight at an altitude of 60,000 feet and a Mach number of 2.0 produced sonic booms which were considered to be tolerable, and it is reasonable t o expect that cruising flight at higher altitudes will produce booms of tolerable intensity for airplanes of the size and weight of the test airplanes. The measured variation of sonic-boom intensity with altitude was in good agreement with the variation calculated by an equation given in NASA Technical Note D-48. The effect of Mach number on the ground overpressure is small between Mach numbers of 1.4 and 2.0, a result in agreement with the theory. No amplification of the shock-wave overpressures due to refraction effects was apparent near the cutoff Mach number. A method for estimating the effect of fligh-path angle on cutoff Mach number is shown. Experimental results indicate agreement with the method, since a climb maneuver produced booms of a much decreased intensity as compared with the intensity of those measured in level flight at about the same altitude and Mach number. Comparison of sound pressure levels for the fighter and bomber airp lanes indicated little effect of either airplane size or weight at an altitude of 40,000 feet.
Lina, Lindsay J.↗
Random Deviations from Cruise Altitudes of a Turbojet Transport at Altitudes of a Turbojet Transport at Altitudes between 20,000 and 41,000 Feet
An evaluation has been made of the random deviations from the cruise altitudes (called flight technical error) of a large turbojet transport on scheduled, passenger-carrying operations over the Eastern United States, the Atlantic Ocean, and Western Europe. Data were collected from l9O flights through an altitude range of 20,000 to 41,000 feet and for a time period from January to August 1959. The results of the investigation, based on an evaluation of the altitude recordings of an NASA VGH recorder, showed that for a high percentage of the total cruise time (99.0 percent) the airplane operated within 100 feet of its stabilized cruise altitude. On occasion, however, the excursions of the airplane from the cruise altitude reached large values (in excess of 1,000 feet in the worst case).
Gracey, William↗
Performance Characteristics of a Preformed Elliptical Parachute at Altitudes between 200,000 and 100,000 Thousand Feet Obtained by In-Flight Photography
The performance characteristics of a pre-formed elliptical parachute at altitudes between 200,000 and 100,000 feet were obtained by means of in-flight photography. The tests demonstrate that this type of parachute will open at altitudes of about 200,000 feet if conditions such as twisting of the suspension lines or draping of the suspension lines over the canopy do not occur. Drag-coefficient values between 0.6 and 0.8 were found to be reasonable for this type of parachute system in the altitude range between 200,000 and 100,000 feet.
Murro, Harold N.↗
Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer: Stringer-Feet Imperfections and Assembly - Part 1
Elastic-plastic, large-deflection nonlinear stress analyses are performed for the external hat-shaped stringers (or stiffeners) on the intertank portion of the Space Shuttle s external tank. These stringers are subjected to assembly strains when the stringers are initially installed on an intertank panel. Four different stringer-feet configurations including the baseline flat-feet, the heels-up, the diving-board, and the toes-up configurations are considered. The assembly procedure is analytically simulated for each of these stringer configurations. The location, size, and amplitude of the strain field associated with the stringer assembly are sensitive to the assumed geometry and assembly procedure. The von Mises stress distributions from these simulations indicate that localized plasticity will develop around the first eight fasteners for each stringer-feet configuration examined. However, only the toes-up configuration resulted in high assembly hoop strains.
Knight, Norman F., Jr.↗
Ground Measurements of the Shock-Wave Noise from Airplanes in Level Flight at Mach Numbers to 1.4 and at Altitudes to 45000 Feet
Time histories of noise pressures near ground level were measured during flight tests of fighter-type airplanes over fairly flat, partly wooded terrain in the e Mach number range between 1.13 and 1.4 and at altitudes from 25,000 to 45,000 feet. Atmospheric soundings and radar tracking studies were made for correlation with the measured noise data. The measured and calculated values of the pressure rise across the shock wave were generally in good agreement. There is a tendency for the theory to overestimate the pressure at locations remote from the track and to underestimate the pressures for conditions of high tailwind at altitude. The measured values of ground-reflection factor averaged about 1.8 f or the surface tested as compared to a theoretical value of 2.0. P o booms were measured in all cases. The observers also generally reported two booms; although, in some cases, only one boom was reported. The shock-wave noise associated with some of the flight tests was judged to be objectionable by ground observers, and in one case the cracking of a plate-glass store window was correlated in time with the passage of the airplane at an altitude of 25,000 feet.
Maglieri, Domenic J.↗
Standard Atmosphere - Tables and Data for Altitudes to 65,800 Feet
Report includes calculated detailed tables of pressures and densities of a standard atmosphere in both metric and english units for altitudes from -5,000 meters to 20,000 meters and from -16,500 feet to 65,800 feet. Tables, figures, physical constants, and basic equations are based upon the text, reproduced herein, of the manual of the ICAO standard atmosphere, International Civil Aviation Organization (ICAO) draft of December 1952. (author)
Source record↗
Charts Depicting Kinematic and Heating Parameters for a Ballistic Reentry at Speeds of 26,000 to 45,000 Feet Per Second
Reentry trajectories, including computations of convective and radiative stagnation-point heat transfer, have been calculated by using equations for a point-mass reentry vehicle entering the atmosphere of a rotating, oblate earth. Velocity was varied from 26,000 to 45,000 feet per second; reentry angle, from the skip limit to -20 deg; ballistic drag parameter, from 50 to 200. Initial altitude was 400,000 feet. Explicit results are presented in charts which were computed for an initial latitude of 38 deg N and an azimuth of 90 deg from north. A method is presented whereby these results may be made valid for a range of initial latitude and azimuth angles.
Lovelace, Uriel M.↗
Analytical Investigation of a Flicker-Type Roll Control for a Mach Number 6 Missile with Aerodynamic Controls Over An Altitude Range of 82,000 to 282,000 feet
An analytical investigation has been carried out to determine the responses of a flicker-type roll control incorporated in a missile which traverses a range of Mach number of 6.3 at an altitude of 82,000 feet to 5.26 at an altitude of 282,000 feet. The missile has 80 deg delta wings in a cruciform arrangement with aerodynamic controls attached to the fuselage near the wing trailing edge and indexed 450 to the wings. Most of the investigation was carried out on an analog computer. Results showed that roll stabilization that may be adequate for many cases can be obtained over the altitude range considered, providing that the rate factor can be changed with altitude. The response would be improved if the control deflection were made larger at the higher altitudes. lag times less than 0.04 second improve the response appreciably. Asymmetries that produce steady rolling moments can be very detrimental to the response in some cases. The wing damping made a negligible contribution to the response.
Lundstrom, Reginald R.↗
Stationary Apparatus Would Apply Forces of Walking to Feet
A proposed apparatus would apply controlled cyclic forces to both feet for the purpose of preventing the loss of bone density in a human subject whose bones are not subjected daily to the mechanical loads of normal activity in normal Earth gravitation. The apparatus was conceived for use by astronauts on long missions in outer space; it could also be used by bedridden patients on Earth, including patients too weak to generate the necessary forces by their own efforts. The apparatus (see figure) would be a modified version of a bicycle-like exercise machine, called the cycle ergometer with vibration isolation system (CEVIS), now aboard the International Space Station. Attached to each CEVIS pedal would be a computer-controlled stress/ vibration exciter connected to the heel portion of a special-purpose pedal. The user would wear custom shoes that would amount to standard bicycle shoes equipped with cleats for secure attachment of the balls of the feet to the special- purpose pedals. If possible, prior to use of the apparatus, the human subject would wear a portable network of recording accelerometers, while walking, jogging, and running. The information thus gathered would be fed to the computer, wherein it would be used to make the exciters apply forces and vibrations closely approximating the forces and vibrations experienced by that individual during normal exercise. It is anticipated that like the forces applied to bones during natural exercise, these artificial forces would stimulate the production of osteoblasts (bone-forming cells), as needed to prevent or retard loss of bone mass. In addition to helping to prevent deterioration of bones, the apparatus could be used in treating a person already suffering from osteoporosis. For this purpose, the magnitude of the applied forces could be reduced, if necessary, to a level at which weak hip and leg bones would still be stimulated to produce osteoblasts without exposing them to the full stresses of walking and thereby risking fracture.
Hauss, Jessica↗
SPECTRO-POLARIMETRIC IMAGING REVEALS HELICAL MAGNETIC FIELDS IN SOLAR PROMINENCE FEET
Solar prominences are clouds of cool plasma levitating above the solar surface and insulated from the million-degree corona by magnetic fields. They form in regions of complex magnetic topology, characterized by non-potential fields, which can evolve abruptly, disintegrating the prominence and ejecting magnetized material into the heliosphere. However, their physics is not yet fully understood because mapping such complex magnetic configurations and their evolution is extremely challenging, and must often be guessed by proxy from photometric observations. Using state-of-the-art spectro-polarimetric data, we reconstruct the structure of the magnetic field in a prominence. We find that prominence feet harbor helical magnetic fields connecting the prominence to the solar surface below.
79 ASTRONOMY AND ASTROPHYSICS↗