Accession Number : ADA299815

Title :   Diamond Dome Oxidation Flight Boundaries.

Descriptive Note : Final rept. Aug-Oct 94,

Corporate Author : NAVAL AIR WARFARE CENTER WEAPONS DIV CHINA LAKE CA

Personal Author(s) : Johnson, Curtis E. ; Dow, Robert L. ; Blanchard, Douglas G.

PDF Url : ADA299815

Report Date : SEP 1995

Pagination or Media Count : 24

Abstract : A parametric study was conducted on the aerodynamic heating of a hypothetical hemispherical diamond dome. Flight was assumed to occur at constant altitude and Mach number. The times required for the maximum temperature on the dome to reach 800, 900, and 1000 deg C were calculated, covering the temperature range where diamond oxidation becomes rapid. The parametric matrix included altitudes from zero to 200,000 ft, and Mach numbers from 3.9 or 4.1 to 8.0. For Mach 5 at sea level, the dome would reach 800 deg C in 4.5 5, 900 deg C in 6.5 s, and 1000 deg C in 9 s, while the total (or stagnation) temperature would be about 1250 deg C. Significant temperature variations throughout the dome were calculated, especially as a function of angular position around the dome. For example, at Mach 5.5 and 20,000 ft the stagnation point of the dome reached 900 deg C in 9 s, while the edge of the dome 90 deg away was 200 deg C cooler. Oxidation would not be a concern for flights up to about Mach 4, while at Mach 5 and above flights would be limited to short durations or high altitudes. Diamond dome temperatures can also be calculated for specific flight profiles, and examples are provided for sample medium and long range anti-air missiles. These studies show that time of flight, speed, and altitude are all key parameters that would affect the oxidation of diamond domes. The information provided is valuable for assessing oxidation-limited flight conditions for diamond domes. jg p.4

Descriptors :   *DIAMONDS, *BOUNDARIES, *OXIDATION, *FLIGHT PATHS, *DOMES(STRUCTURAL FORMS), *AERODYNAMIC HEATING, GUIDED MISSILES, ANGLES, POSITION(LOCATION), TEMPERATURE, PARAMETRIC ANALYSIS, TIME, VARIATIONS, SHORT RANGE(TIME), PROFILES, LONG RANGE(DISTANCE), HIGH ALTITUDE, MACH NUMBER, RANGE(EXTREMES), ALTITUDE, HEMISPHERES, SEA LEVEL, ANTIAIRCRAFT MISSILES, STAGNATION POINT.

Subject Categories : Aerodynamics
      Inorganic Chemistry
      Physical Chemistry
      Structural Engineering and Building Technology

Distribution Statement : APPROVED FOR PUBLIC RELEASE