An Evaluation of the Modified Sachs and Ledsham-Pike Scaling of a Nuclear Air Blast
Abstract
The accuracy of modified Sachs and Ledsham-Pike scaling of peak shock hydrodynamic variables from a nuclear burst in air is evaluated. The modified Sachs and Ledsham-Pike methods are corrections applied to the similarity transform which is used to compute shock overpressures and related variables for infinite homogeneous atmospheric ambient conditions. This similarity transform no longer applies when the burst and target are located at different altitudes, and the modified Sachs and Ledsham-Pike corrections are applied to account for these varying ambient conditions. In this dissertation, the modified Sachs shock positions, dynamic pressures, and overpressures and the Ledsham-Pike overpressures are compared to a fully two dimensional flux-corrected transport finite difference solution. The flux-corrected transport method maintains a sharp and steady shock with no oscillations. The numerical calculations include a real atmospheric model, the Doan and Nickel equation of state of air, and radiation energy losses. It is found that the modified Sachs and Ledsham-Pike overpressures are essentially identical, and that their overpressures compare with the numerical results more favorably in the ascending directions than in the descending directions. A new Ledsham-Pike correction factor is presented for the descending directions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1983
- Accession Number
- ADA140653
Entities
People
- Michael L. Crawford
Organizations
- Air Force Institute of Technology