EXPERIMENTAL AND THEORETICAL INVESTIGATION OF TEMPERATURES AND STRESSES IN ABLATING THICK-WALLED HEMISPHERES.
Abstract
Hypersonic wind tunnel tests of 7 3/4 inch diameter Plexiglas and Nylon hemispheres were designed and conducted at the Preston R. Bassett Laboratory of the Polytechnic Institute of Brooklyn. A shrouded model technique was utilized to simulate Mach 15 to 20 flight. The models were instrumented with thermocouples and strain gages from which continuous time histories of temperature and strain were recorded. In addition, ablation measurements were made after the models were tested. The experimental results were compared with theoretical calculations of strain, temperature and ablation. A point-symmetric ablation and temperature analysis was conducted using a heat balance technique. The assumed temperature profiles were used in a point-symmetric thermal stress analysis in which a variation of the modulus of elasticity with temperature was approximated by using a concentric layer technique. The relative accuracy of this latter technique was determined by comparison with a perturbation solution for continuously varying modulus of elasticity. The effect of axisymmetric pressure distributions, as well as the boundary condition imposed by the model support, was considered in an axisymmetric layer analysis. A comparison between theory and experiment indicates good qualitative results and good to poor quantitative results. The details of the analyses, and the comparison between the theoretical predictions and experiment are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1967
- Accession Number
- AD0663154
Entities
People
- Richard F. Parisse
- S. V. Nardo
Organizations
- New York University Tandon School of Engineering