Temperature-Step Effects on Direct Measurement of Skin-Friction Drag.
Abstract
Wall-temperature discontinuities can occur in skin-friction balance tests whenever a balance drag element is thermally insulated from the surrounding test surface. An experimental study was conducted to investigate the effects of such a temperature step on the local friction drag. A temperature step was produced by varying the temperature of the NSWC skin-friction-balance drag element above the temperature of the surrounding nozzle wall. Drag-element temperatures ranged from 100 K to 240 K with the surrounding wall maintained at a temperature of 89 K. Nominal Mach numbers were 2.9 and 4.9 over a unit Reynolds number range of 2.6 to 20 million per meter. The results show that the value of the measured shear stress is higher than the cold wall value for a drag element which is at a higher temperature than the surrounding wall temperature and the change in shear stress is proportional to the difference between the drag element and the surrounding wall temperatures. The data has been correlated and corrections to previously published skin-friction results are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 07, 1977
- Accession Number
- ADA051340
Entities
People
- Robert L. P. Voisinet
Organizations
- Naval Ordnance Laboratory