Initial decay of flow properties of planar, cylindrical and spherical blast waves
Abstract
Analytical expressions are presented for the initial decay of all major flow properties just behind planar, cylindrical, and spherical shock wave fronts whose trajectories are known as a function of either distance versus time or shock overpressure versus distance. These expressions give the time and/or distance derivatives of the flow properties not only along constant time and distance lines but also along positive and negative characteristic lines and a fluidparticle path. Conventional continuity, momentum and energy equations for the nonstationary motion of an inviscid, nonheat conducting, compressible gas are used in their derivation, along with the equation of state of a perfect gas. All analytical expressions are validated by comparing the results to those obtained indirectly from known selfsimilar solutions for planar, cylindrical and spherical shockwave flows generated both by a sudden energy release and by a moving piston. Futhermore, time derivatives of pressure and flow velocity are compared to experimental data from trinitrotoluene (TNT), pentolite, ammonium nitratefuel oil (ANFO) and propaneoxygen explosions, and good agreement is obtained.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 October 1983
 Bibcode:
 1983STIN...8412416S
 Keywords:

 Explosions;
 Flow Characteristics;
 Shock Fronts;
 Shock Waves;
 Ammonium Nitrates;
 Compressible Flow;
 Gas Flow;
 Propane;
 Trajectories;
 Trinitrotoluene;
 Fluid Mechanics and Heat Transfer