Accession Number:

AD0600341

Title:

A COMPARISON OF SHOCK AND ISENTROPIC HEATING IN LIGHT-GAS GUN COMPRESSION.

Descriptive Note:

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

Report Date:

1964-04-13

Pagination or Media Count:

9.0

Abstract:

An ideal model of light-gas gun operation that permits the evaluation of the effectiveness of shock heating in the light gas as opposed to the heating due to isentropic compression is hypothesized. This model assumes a shock wave generated by a piston which is instantly accelerated to some constant velocity. After the shock wave traverses the compression tube of the gun four times, it is followed by isentropic compression which absorbs all of the piston energy. The temperatures arrived at by shock compression and isentropic compression are compared when the pressures of the final states are equal. The results indicate that for reasonably fast pistons around 6000 fps, the ideal temperature gains are on the order of 30 percent and the corresponding sound speed gains are only about 15 percent. The resulting increase in projectile velocity under these conditions cannot exceed 15 percent. Real gas effects would be expected to make this value still lower. It is concluded consequently, especially for the gun configurations currently used at NRL, that shock heating is not an important factor in the gun operation nor a particularly fruitful means of enhancing gun performance. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE