Crew Compartment Vibration Environment in The B-52Aircraft during Low-Altitude,High-Speed Flight.

摘要

Measurements were made of the pilot station vibration environment experienced in the B-52aircraft during low-altitude,high-speed flight. Data were obtained of the longitudinal,lateral and vertical linear accelerations and the roll axis angular velocities and accelerations. The terrain contour following flights at 500-900feet above the flat to semi-mountainous regions of Louisiana and Arkansas were made at 350knots true airspeed. Data analyses included probability density and distribution and the auto-power spectral density functions in addition to tests for stationarity,randomness and normality. The individual degree-of-freedom results are presented in graphical and tabular form and in general indicate that the pilot station vibration environment produced by the combination of gust response and maneuvering: (1) is stationary for up to 590seconds; (2) is a random phenomena that does not satisfy the chi-square goodness-of-fit test for Gaussian distribution; (3) cannot be adequately simulated in the laboratory for human biomedical tolerance and/or psycho-physiological performance studies using only vertical axis motion; (4) is remarkably in agreement with those PSD's calculated for the lateral and vertical axes using an aircraft transfer function experimentally derived on another program and the Dryden gust input spectrum. (Author)