Accession Number : ADA194691

Title :   Analytic Solutions to the Closed Bomb

Descriptive Note : Technical rept. 1985-1986

Corporate Author : ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Robbins, Frederick W. ; Lynn, Franz R.

PDF Url : ADA194691

Report Date : MAR 1988

Pagination or Media Count : 85

Abstract : Closed vessel tests are routinely performed to determine the linear burning rates of solid propellants for interior ballistic studies. Generation of synthetic pressure traces to simulate closed vessel firings is done to validate new burning rate reduction programs, test extensions to existing models, assess the sensitivity of computational algorithms to different methods of smoothing and differentiating the fundamental pressure data, and provide predictions for guiding the decisions of test engineers. These needs became acutely evident in the JANNAF-sponsored round robin on closed bomb methods when some easily communicated validation and comparison procedure would have been very useful. The general problem of synthesizing closed vessel pressure data can be simplified by means of a number of assumptions which then allow two closed-form finite solutions for a charge of single perforated grains. Seven algebraic formulas are derived which permit easy computer calculation of the pressure, depth burned, mass burned, their respective derivatives, and instantaneous surface area which can then be used as input to a burning rate reduction program. The first assumes the covolume equals the reciprocal of the density; the second removes this restriction. Keywords: Closed bomb tests; Synthesizing pressure time; Fortran.

Descriptors :   *MATHEMATICAL ANALYSIS, *IGNITION, *CLOSED BOMB TESTS, *SOLID PROPELLANTS, COMPUTER PROGRAMS, ALGORITHMS, COMPUTATIONS, FIRING TESTS(ORDNANCE), TEST METHODS, SENSITIVITY, FORTRAN, BURNING RATE, COMPUTER AIDED DIAGNOSIS, INTERIOR BALLISTICS.

Subject Categories : Ammunition and Explosives
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE