The boundary-layer flow, for instance along a sonar dome, gives rise to hydrodynamic noise due to the pressure fluctuations. The prediction of the resulting self-noise received by the sonar antenna is based on models, which in general take only partially into account the flexibility of the dome wall. The present work readdresses the problem of hydrodynamic noise, considering the geometrically simplified model of a two-dimensional unstable boundary-layer flow along an elastic plate with clamped ends. The incompressible Navier-Stokes equations are fully coupled to the elastic plate model and the system is numerically solved for various plate materials. The unstable flow dynamics is analyzed with respect to the wall properties. The Fourier-transformed stress tensor is then used in the framework of Lighthill's analogy to determine the generated radiative sound, emphasizing the effect of wall-flexibility. This work is supported by Thales Underwater System and DCNS.

The purpose of this study was to examine the psychometric properties of the recently developed Multidimensional Diabetes Questionnaire (MDQ). The MDQ which is theoretically linked to a social learning perspective of diabetes, was designed to provide a comprehensive assessment of diabetes-related cognitive and social factors. It includes 41 items grouped into three sections: (1) perceptions related to diabetes and related social support, (2) positive and misguided reinforcing behaviors related to self-care activities, and (3) self-efficacy and outcome expectancies. Confirmatory factor analyses, conducted on a sample of 249 patients with non-insulin-dependant diabetes mellitus, supported the construct validity of the MDQ. Adequate internal consistency and significant demographic, psychological, behavioral, and disease-related correlates were found. The MDQ may prove valuable in understanding individual differences in adjustment to diabetes.

An experimental-analytical technique was developed to evaluate the noise produced inside various types of sonar domes under the effect of a turbulent flow, in a frequency range where the structure has a high modal density. The transfer functions between a punctual external force applied to the dome and the acoustic pressure at a point inside the cavity was measured on a scale model. This measure was made using a reciprocity technique with emitting hydrophones within the cavity and with accelerometers all over the dome's external surface. The noise level at a point inside the cavity is calculated from these experimental transfer functions and a turbulent boundary layer wall pressure model. The wave vector frequency spectrum model used is Chase's model [D. M. Chase, J. Sound Vib. 70, 29–67 (1980)], adjusted according to the local parameters of the flow. The results obtained with this method agree with experimental results. In order to test various types of structure, this technique on a scale model has considerable advantages compared with experimentations on a real structure: limited expense, experimental ease, and reliability.