Auxiliary Equipment and Techniques for Adapting the Constant-Temperature Hot-Wire Anemometer to Specific Problems in Air-Flow Measurements

摘要

The constant-temperature hot-wire anemometer amplifier and accessories have been developed to provide an instrument with wide frequency response, good stability, and ease of operation. Auxiliary equipment has been developed to provide heating currents for large wires, to make average-square computations, and to make double-correlation coefficient measurements. Techniques are described for using this equipment to study periodic phenomena such as surge, rotating stall, and wake surveys in centrifugal and axial-flow compressors. The application of the equipment to the study of nonperiodic phenomena such as intensity, scale, and spectra of isotropic turbulence is also discussed. Heat-loss data for standardized tungsten wire probes show that no wire calibration is necessary if accuracies of +/- 5 percent are sufficient.