Air-Blast Phenomena as Affected by Terrain
Abstract
The objective of Project 1.8c was to obtain data on effects of gross variations of terrain upon a blast wave produced by nuclear explosion, particularly at ground ranges of importance to moderately hard targets. On Shot Smoky (48 kt, 700-foot height of burst), total-head pressure, pitot-tube dynamic pressure, and overpressure were measured: (1) on both sides of a ridge that rose 280 feet to a crest about 2,600 feet from ground zero and (2) at several equivalent ground ranges along relatively smooth terrain. A precursor formed over both flat and ridge blast lines. The wave forms are not pure types and do not lend themselves to definite classification. Surface-level wave-front-propagation velocities indicate enhanced thermal effects on the front slope of the ridge and a strong diffraction effect as the wave passed over the top of the ridge. Generally, the ridge appeared to provide no real protection from overpressure, with increased overpressures noted on the front face and near the bottom of the back slope. However, the ridge appeared to offer considerable protection to drag-sensitive targets along the back slope and at the foot of the back slope. No significant pressure spikes were observed on the ridge line; the precursor-type blast wave probably prohibited this effect.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 06, 1957
- Accession Number
- AD0337904
Entities
People
- D. C. Sachs
- L. M. Swift
Organizations
- SRI International