Investigations of Ablation Surface Cross-Hatching.
Abstract
The Ablation-Surface Cross-Hatching Program is one of several programs directed toward understanding and suppressing cross-hatched patterns on ablating surfaces. It consists of two wind tunnel studies with analyses which are reported herein: First, an investigation of the phasing of the pressure and temperature distributions over a two-dimensional nonablating wavy wall confirmed in-house theoretical predictions. It is believed this is the first time that heat transfer and insulated wall temperature phasing correspondence to pressure in the cross-hatching process has been theoretically proved and experimentally confirmed. An unexpected cusping of pressure was found at transonic speeds. Second, hypersonic wind tunnel tests, including six-component force measurements, of conical camphor and Korotherm models extended the cross-hatching angle versus edge Mach number correlation; showed nose tip bluntness effects compatible with this correlation and showed that roll torques produced as a result of windward meridian shift after pattern formation are stable. A pre-cross-hatched nonablating model confirmed cross-hatching experience by indicating higher heat transfer to the valleys than to the ridges.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1970
- Accession Number
- AD0874560
Entities
People
- Edgar P. Williams
- George R. Inger