Method of determining laminar turbulent boundary layer impact in cryo-stream and cryo-channel

摘要

The determination method involves feeding an indicator fluid into the cryostream. This has a low impact on the model in the stream, in solid form. The boundary layer impact can then be determined with those positions at which the indicator disappears quicker under the turbulent flow than under the laminar flow. The indicator fluid is fed into the cryo-fluid as a gas. It impacts the model in crystalline form and then disappears under turbulent flow by fast sublimation. Preferably the indicator gas is fed into a cryo-channel by means of a movable lance (15). Preferably carbon dioxide is used as the indicator gas.