Application of horsepower absorption techniques to turboshaft engine testing

This investigation is an attempt to develop a standardized matrix for identifying the optimal horsepower absorber to utilize for a particular turboshaft engine test. Previous efforts identified optimal absorbers within a given family of devices for a particular facility or engine type. Herein, after a historical perspective, the several types of horsepower absorbers currently in industry-wide use are generalized with respect to their performance and operating tendencies. An in-depth analysis of each device's operating principles is coupled with an analysis of each device's positive and negative operating characteristics, thereby illustrating necessary trade-off factors. A discussion of current procedures for turboshaft engine testing is included to define the potential device use environment. An in-depth discussion and qualitative analysis of current turboshaft engine applications is carried out to provide an appreciation for the load modeling considerations necessary in turboshaft engine testing. Modeling requirements, device characteristics, and testing procedure considerations are combined to form a "Test Matrix" rank-ordering the possible choices of horsepower absorbers for a given test. A possible configuration for test facilities utilizing all types of devices is given along with a discussion of possible data incompatibility issues.