Foreign Research Progress: Translations Issued by the N.A.C.A. of Enemy and Allied Reports

A method for recording the local heat‐transfer coefficients on bodies in flow was developed. The cylinder surface was kept at constant temperature by the condensation of vapour except for a narrow strip which is heated separately to the same temperature by electricity. The heat‐transfer coefficient at each point was determined from the electric‐heat output and the temperature increase. The distribution of the heat transfer along the circumference of cylinders was recorded over a range of Reynolds numbers of from 5000 to 426,000. The pressure distribution was measured at the same time. At Reynolds numbers up to around 100,000 high maxima of the heat transfer occurred in the forward stagnation point at 0 deg, and on the rear side at 180 deg., while at around 80 deg. the heat‐transfer coefficient on both sides of the cylinder behind the forward stagnation point manifested distinct minima. Two other maxima occurred at around 115 deg. behind the forward stagnation point between 170,000 and 426,000. At 426,000 the heat transfer at the location of the maxima was almost twice as great as in the forward stagnation point, and the rear half of the cylinder diffused about 60 per cent of the entire heat. The tests are compared with the results of other experimental and theoretical investigations.