Desirable features of an infrared imaging system for aerodynamic research

摘要

Abstract: Advantage of non-intrusiveness, capability for field measurement, and increased availability of infrared imaging systems have resulted in their wider use for aerodynamic research. However, certain difficulties persist while using currently available systems for such applications. A critical evaluation of the infrared imaging systems is presented on the basis of the state- of-the-art of infrared imaging technology and experiences in wind tunnel and flight testing at NASA's Langley Research Center. The requirements for using infrared thermography as a measurement tool in aerodynamic research are examined in terms of range, sensitivity, and accuracy of temperature measurement, temporal and spatial resolution, and features of target. Deficiencies of present infrared imaging systems are identified, and user precautions to avoid such problems by proper selection and operation of these units are suggested. Different aspects of imager performance such as imager optics, video capabilities, and environmental tolerance are discussed. Electronic data recording and image processing hardware and software requirements are evaluated. Slit response tests and spatial resolution are discussed with the objective of obtaining reliable, accurate, and meaningful information from infrared thermography measurements for aerodynamic studies.!17