Installation Effects on Heat Transfer Measurements for a Turbine Vane
Abstract
Experiments have been conducted for a modern high pressure turbine vane in the USAF Turbine Research Facility (TRF). This turbine vane was instrumented with two types of heat flux gauges. The first was a thin film Upilex gauge design wrapped over the full airfoil surface, while the second consisted of Pyrex insert type gauges. Initial measurements showed significant discrepancies in the resultant Nusselt number from these two types of gauges. As the inlet Reynolds number was decreased, these discrepancies collapsed to single laminar level Nusselt number. This suggested a potential change in the flowfield for one of the gauge types. Interrogation of the vane surface metrology showed depressions in the epoxy filler between the Pyrex insert and the metal airfoil. After filling these depressions, the vane was reinstalled and identical tests repeated. This second test revealed a better comparison for two of the Pyrex insert gauges while minimal change resulted in two other gauges. Similar results were achieved for the range of Reynolds numbers tested in laminar, transitional, and turbulent regions for the airfoil. These results suggest that further installation effects may still be present in the Pyrex gauges. Such alterations in the flow field can lead to misleading results and costly errors when applying experimental rig data to turbine design.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2003
- Accession Number
- ADA419243
Entities
People
- Chris R. Joe
- Marc D. Polanka
- Matthew Meininger
Organizations
- Air Force Research Laboratory