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Review: Airblast effects

Abstract

Long Range Airblast Propagation On February 2, 1951, the Atomic Energy Commission discovered that airblast from an 8-kt explosion could break many windows in Las Vegas at 60 miles range from Frenchman's Flat. Yet later, on February 6, only minor effects resulted from three times as large a yield. Atmospheric conditions were found to be responsible for this apparent anomaly. A weather watch was initiated under the direction of Everett Cox to help prevent recurrences during further atmospheric nuclear testing. Our atmosphere with its stratifications of temperature and winds acts as an acoustic lens which may trap, duct, or even focus blast waves from explosions. The basic refraction mechanism is described. Sound speed is proportional to the square root of absolute temperature, as shown in Newton's Principia, so as temperature decreases with altitude, so does sound speed. The proper coefficient was found by Laplace, using adiabatic rather than Newton's isothermal compression. Sound or blast waves propagate through moving air with this wind added or subtracted from the sound speed. This affects an initially vertical plane wave to make it increasingly distorted with time. Wave normals, or rays, are bent upward, away from ground, in layers where net sound velocity decreases  More>>
Authors:
Reed, Jack W [1] 
  1. Sandia Laboratories, Albuquerque, NM (United States)
Publication Date:
May 15, 1970
Product Type:
Conference
Report Number:
CONF-700101(vol.2); INIS-XA-N-229
Resource Relation:
Conference: Symposium on engineering with nuclear explosives, Las Vegas, NV (United States), 14-16 Jan 1970; Other Information: 36 refs, 23 figs; Related Information: In: Symposium on engineering with nuclear explosives. Proceedings. Volume 2, 935 pages.
Subject:
42 ENGINEERING; ATMOSPHERIC CIRCULATION; ATMOSPHERIC EXPLOSIONS; BLAST EFFECTS; COMPUTER CALCULATIONS; ISOTHERMAL PROCESSES; WAVE PROPAGATION
OSTI ID:
20768851
Research Organizations:
American Nuclear Society, Hindsdale, IL (United States); United States Atomic Energy Commission (United States)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
TRN: XA04N0922075318
Availability:
Available from INIS in electronic form
Submitting Site:
INIS
Size:
page(s) 1485-1507
Announcement Date:
Sep 23, 2006

Citation Formats

Reed, Jack W. Review: Airblast effects. IAEA: N. p., 1970. Web.
Reed, Jack W. Review: Airblast effects. IAEA.
Reed, Jack W. 1970. "Review: Airblast effects." IAEA.
@misc{etde_20768851,
title = {Review: Airblast effects}
author = {Reed, Jack W}
abstractNote = {Long Range Airblast Propagation On February 2, 1951, the Atomic Energy Commission discovered that airblast from an 8-kt explosion could break many windows in Las Vegas at 60 miles range from Frenchman's Flat. Yet later, on February 6, only minor effects resulted from three times as large a yield. Atmospheric conditions were found to be responsible for this apparent anomaly. A weather watch was initiated under the direction of Everett Cox to help prevent recurrences during further atmospheric nuclear testing. Our atmosphere with its stratifications of temperature and winds acts as an acoustic lens which may trap, duct, or even focus blast waves from explosions. The basic refraction mechanism is described. Sound speed is proportional to the square root of absolute temperature, as shown in Newton's Principia, so as temperature decreases with altitude, so does sound speed. The proper coefficient was found by Laplace, using adiabatic rather than Newton's isothermal compression. Sound or blast waves propagate through moving air with this wind added or subtracted from the sound speed. This affects an initially vertical plane wave to make it increasingly distorted with time. Wave normals, or rays, are bent upward, away from ground, in layers where net sound velocity decreases with altitude and are bent downward where sound velocity increases with altitude. This bending, applied to a point sound source or explosion, gives ray paths typified. Where dueling is caused by a velocity inversion high above the ground, there is a zone of silence beyond the immediate range of the strong explosion wave, and a sound ring at some distance determined by the height and strength of the dueling layer. Calculation of ray paths has evolved with the growth in needs and computer capabilities.}
place = {IAEA}
year = {1970}
month = {May}
}