Atmospheric attenuation of explosion waves

Abstract

Observations of sound attenuation in the out of doors have shown an attenuation factor approximately dependent on the five-fourths power of frequency, rather than the square. Both power laws have been applied to calculations of yield-scalable pressure signatures from explosions to allow comparison of results with measurements of explosion-wave compression rise times. It appears that the five-fourths law better explains the long rise times observed, but there are still serious underpredictions. Nevertheless, this model has been applied to the problem of determining the requirements for pressure-gauge frequency response. At the low overpressures of concern in environmental monitoring, it appears that a 1-kHz instrument response is more than adequate for recording explosion waves.

Experimental and numerical studies of weak blast waves in air

“…The decay of the positive overpressure is expressed as Ap/ oc r -1"3s. The index of 1.38 is close to the observed value of 1.4 in the field experiments for the corresponding range of peak overpressure (Reed 1977;Baker 1973). In the spark discharge data of Orenstein (1982), it is 1.27…”

“…Numerous open field experiments were conducted and the decay of blast waves were observed for long distances, up to the kilometer range (Reed 1977;Baker 1973). On the other hand, small scale laboratory experiments have also been conducted in the range of a few meters with spark discharges (Ribner et al 1973;Anderson 1974;Tubb 1975;Orenstein 1982).…”

Estimates of meteoroid kinetic energies from observations of infrasonic airwaves

“…Comparison of the small bolide peak-to-peak amplitude curve to standard American National Standards Institute (ANSI) overpressure-distance curves (American National Standards Institute, 1983) for a 1 kt nuclear explosion (NE) and an 1134 kg (2500 lb) high yield chemical explosion (HE) (Reed, 1977), show distinct differences in both amplitude and slope (Fig. 10a).…”

Sound Exposure Calculations for Transient Events and Other Improvements to an Acoustical Tactical Decision Aid

“…• Reed (1977) explosion model. Reed (1977) points out that the exponential model poorly describes the negative pressure phase of an explosion and offers the following equation as an alternative:…”