A thermographic method to map the local heat transfer coefficient on the complete surface of a circular cylinder in an airflow
Résumé
A constant wall heat flux method was developed to map the transfer coefficient value at the surface of a circular cylinder whose height to diameter ratio was 3. The cylinder was positioned either cross-flow or sloped at 45∘ into the flow. Preliminary experiments showed that the heat flux had to be generated nearly all over the body to avoid surface conduction which meant it was difficult to make the sample. The surface temperatures were measured by an infrared camera which was located outside the experimental cell to avoid flow disturbances. Procedures were developed to be able: (i) to the get infrared pictures through a window and (ii) to rebuild from these pictures and without distortion the complete distribution of the heat transfer coefficient at the surface of the cylinder.