Vibration measurements of an airplane fuselage structure I. Turbulent boundary layer excitation

A Wavenumber Approach to Modelling the Response of a Randomly Excited Panel, Part Ii: Application to Aircraft Panels Excited by a Turbulent Boundary Layer

“…Table 2 (column 5) also presents the "rst eigenfrequencies of a curved aircraft panel which are obtained from the analytical approximations given by Blevins [39]. We have used a typical circumferential radius of 2 m [8]. One can see that the curvature raises the natural frequencies of a curved panel above that of an analogous #at plate by a factor of up to about 1)3, but in a non-uniform way.…”

“…number of structural modes is accounted for: } } } }, (3, 6), -) -) -, (3, 7); ) ) ) ), (4, 7); 00, (6, 10); 00, (8,12). Figure 2 shows the "rst coe$cients of the self-modal excitation terms KL of series (80) (Part I) as a function of frequency.…”

“…The vertical and horizontal dimensions of these panels correspond to the distance between two adjacent frames and two adjacent stringers respectively. The validity of this model has been con"rmed as representative by extensive #ight test measurements conducted by Boeing and carried out on the forward and rear part of an airplane fuselage under cruise conditions [7,8]. These data have shown that, from 500 Hz to 1)5 kHz, the boundary layer noise is preponderant and excites the forward part of the fuselage in such a way that the #ow-induced vibrations are only correlated over a single fuselage bay in the streamwise direction.…”

Application of the Spectral Finite Element Method to Turbulent Boundary Layer Induced Vibration of Plates

“…Equation (28) is substituted as the pressure pðx; yÞ into equation (1). For a given m 0 and transverse mode n; p x ¼ F 0 ðsinðnpy s =bÞe Ài2m 0 px s =2l x =l x bÞe Àið2m 0 p=2l x Þx : Figure 3 shows the resulting plate mean square velocity with the described pressure excitation and also the exact response to the point force calculated from equation (B2).…”

“…The vibrations induced by fluctuating flow may lead to structural fatigue [1] and may also be the source of excessive noise. Specifically these fluctuations arise when, at high speeds, a vehicle is propelled through a fluid or when the fluid is transmitted through a duct or pipe.…”