This article summarizes the capabilities and development of the Helios version 2.0, or Shasta, software for rotary wing simulations. Specific capabilities enabled by Shasta include off-body adaptive mesh refinement and the ability to handle multiple interacting rotorcraft components such as the fuselage, rotors, flaps and stores. In addition, a new run-mode to handle maneuvering flight has been added. Fundamental changes of the Helios interfaces have been introduced to streamline the integration of these capabilities. Various modifications have also been carried out in the underlying modules for near-body solution, off-body solution, domain connectivity, rotor fluid structure interface and comprehensive analysis to accommodate these interfaces and to enhance operational robustness and efficiency. Results are presented to demonstrate the mesh adaptation features of the software for the NACA0015 wing, TRAM rotor in hover and the UH-60A in forward flight.

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The mechanical behavior at soil-structure interface (SSI) has a crucial influence on the safety and stability of geotechnical structures. However, the behavior of SSI under constant normal stiffness condition from micro to macro scale receives little attention. In this study, the frictional characteristics of SSI and the associated displacement localization under constant normal stiffness condition are investigated at both macro-and microscales by simulating a series of interface shear tests with discrete element method (DEM). The algorithm to achieve a constant normal stiffness is first developed. The macroscopic mechanical response of the interface shear tests with both loose and dense specimens at various normal stiffness is discussed in terms of shear stress, normal stress, vertical displacement, horizontal displacement and stress ratio. Then the microscopic behaviors and properties, including shear zone formation, localized void ratio, coordination number, force chains and soil fabric are investigated. The effect of normal stiffness is thus clarified at both macro-and microscales.

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Bacillus fusiformis CGMCC1347, screened from soil, was immobilized successfully to biotransform isoeugenol to vanillin. The optimal immobilization conditions were 2.5% sodium alginate, 10% cell density and Ca2+ 0.1 mol l-1. The optimal reaction conditions in a 2 L CSTR reactor with immobilized Bacillus fusiformis CGMCC1347 cells were isoeugenol 600 mL, immobilized cells 400 g, pH 3.5 dH2O 400 mL, 37 oC, 200 r min-1 shaking speed and 0.8 vvm air capacity. The average vanillin concentration reached 39.26 g l-1 after 6 times reuse of immobilized cells in 2 L CSTR.