Use of a New Analytical Technique to Determine Heat Input from Inner Surface Temperatures Measured on a Hemispherical Shell during a Free Flight Experiment.
Abstract
A free flight experiment has been conducted on a hemispherical shell to test a new technique for deriving outer surface temperature and heat transfer distributions from inner surface temperature measurements recorded from three arrays of thermocouples. The hemispherical shell which was mounted on the front of a rocket vehicle reached a maximum Mach number of 5.5 at 4 km altitude after 7 s of flight. Derived heat transfer profiles are characteristic of boundary layer flow which is laminar in the stagnation region, changing to turbulent within the first twenty degrees of arc. For the maximum heating profile, Stanton numbers varied between 0.0037 at 30 deg from the stagnation point and 0.0025 at 60 deg. The maximum free stream Reynolds number based on body diameter was 26 million. Agreement with laminar stagnation point heat transfer theory for steady flow is good except for just after maximum heating where the experimental results are some twenty five per cent higher. It is concluded that the new technique is successful but that the circumferential temperature and heat transfer resolutions could be improved by increasing the number of thermocouples in each array from seven to at least nine. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1979
- Accession Number
- ADA086967
Entities
People
- G. Jepps