Imaging Findings of the Morel-Lavellée Lesion

Introduction: This study aims to evaluate the magnetic resonance imaging (MRI) findings of the Morel-Lavellée lesion (MLL),which described as degloving injury of the subcutaneous fatty tissue.Methods: MRI features of fifteen patients in whom the diagnosis of MLL was established by clinically or surgery retrospec-tively analyzed.Results: All the lesions were located in the lower extremities, and 86.6% (n=13) were located at the knee level or above. Alllesions had an anatomic relationship with deep fascia. The majority of the lesions were in either fusiform or crescentic form.60% (n=9) of the lesions showed a well-defined smooth contour. Pseudocapsules were observed in nine patients (60%).46.6% (n=7) of the lesions had a homogeneous signal property. The intralesional hemorrhagic signal was observed in 26.6%(n=4) of the lesions and intra-lesional fat signal in 46.6% (n=7). One patient had fluid-fluid leveling. In two cases, muscleinjury were accompanied by the MLL. In all cases, no associated bone lesion was noted.Discussion and Conclusion: MLL should be considered if a well-circumscribed, crescentic or fusiform subcutaneous masslesion in association with the deep fascia is present, especially in the presence of a history of previous trauma

Development of an efficient numerical method for wind turbine flow, sound generation, and propagation under multi-wake conditions

The propagation of aerodynamic noise from multi-wind turbines is studied. An efficient hybrid method is developed to jointly predict the aerodynamic and aeroacoustics performances of wind turbines, such as blade loading, rotor power, rotor aerodynamic noise sources, and propagation of noise. This numerical method combined the simulations of wind turbine flow, noise source and its propagation which is solved for long propagation path and under complex flow environment. The results from computational fluid dynamics (CFD) calculations not only provide wind turbine power and thrust information, but also provide detailed wake flow. The wake flow is computed with a 2D actuator disc (AD) method that is based on the axisymmetric flow assumption. The relative inflow velocity and angle of attack (AOA) of each blade element form input data to the noise source model. The noise source is also the initial condition for the wave equation that solves long distance noise propagation in frequency domain. Simulations were conducted under different atmospheric conditions which showed that wake flow is an important part that has to be included in wind turbine noise propagation