Numerical aerodynamic investigations on stratospheric airships of different tail configurations
Numerical investigations on stratospheric airships of different tail configurations are conducted based on the Reynolds-averaged N-S equations and k-ω SST turbulent model in the condition of the same volume and total area of the tails. The influence of tail configurations on the force and moment characteristics as well as flow phenomena on both hull and fins are analyzed. In particular, the hull-fin mutual interference effect is discussed compared to the bare hull performance. It is found that a cross-shaped tail produces a superior lift characteristic and stability at high angle but greater drag due to horizontal fins, both in pitch and yaw channels than the inverted Y and X shaped tail. The hull-fin interference generates additional hull lift, drag and an offsetting moment and causes side edge separation on the suction side of horizontal (side) fins in the cross (inverted Y and X shaped) tail configuration. The inverted Y-shaped tail provides the greatest interference drag. These investigations serve to provide references for airship configuration design.
Numerical Investigation on the Aeroelastic Behavior of an Airship with Hull-Fin Configuration
Numerical investigation was conducted on an airship of hull-fin configuration for aerodynamic and aeroelastic characteristics in three-dimensional viscous flows. The mathematical model was built and the corresponding numerical code was developed for the fluid-structure interaction problem. The governing equations of the viscous flow with LL-Low Reynolds modified model were solved by the standard SIMPLE algorithm based on the finite volume method. A fluid-structure coupled method was employed to solve the nonlinear aeroelasticity problem for the airship. The computational results of the viscous flow are in good agreement with the experimental measurements. The simulation on the aeroelastic behavior of the airship in a trimmed flight reveals the effect of structure flexibility on the aerodynamic performance.
Constructing gender and locality in late medieval England : the lives of Anglo-Saxon and British female saints in the South English Legendaries
..........................................................................................2 Acknowledgements.............................................................................5 Introduction....................................................................................8 1. Female Saints in the SELS 2. The SEL Manuscripts of Monastic Women’s Lives 3. Narratives of Medieval Monastic Women Chapter 1 Saint Frideswide of Oxford and Topoi of Virginity........................42