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Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the complex multiphase flow of supersonic gas jets in still water, an underwater ignition experiment of solid rocket motor is conducted in the pressure tank, and the numerically simulated results of gas-water coupling for the same case are obtained by using Reynolds-averaged Navier-Stokes(RANS) method and volume of fluid(VOF) model. The results show that, after underwater gas jets achieve supersonic flow, the gas bubble appears to be cap-like due to the jet impact effect. Then the gas bubble gradually evolves into an ellipsoid-shaped gasbag with average axial expansion velocity of about 40 m/s. The flow structures inside the gas bubble are very complex, where two shear vortex rings and repeated shock cells exist. The interaction between the boundaries of gas jet and gas bubble may induce the instability of gas jet in the subsequent evolution stage. It is also demonstrated that there exists a part of high pressure in the flow field, and the pressure peaks gradually match with the environmental pressure in the oscillation process. The pressure of opening nozzle closure and the area of nozzle outlet are the two important factors that affects thrust peak value. [ABSTRACT FROM AUTHOR]

A set of conceptual sketch for the near-space high supersonic (Mα = 3.5) unmanned aerial vehicle (UAV) is derived from the idea of integration of aerodynamic configuration and propulsion system. An accurate and straight-forward parametric geometry modeling for the near-space high supersonic UAV is essential to rapidly implement and evaluate the conceptual design. A geometry parameterization method for accurate description of the UAV configuration is proposed by use of shape function/class function transformation, Lagrange interpolation polynomial and B-spline curve. Based on the geometry parameterization, a code written in visual basic (VB) language is developed through the creation of macros from the CATIA application, which is used to implement the automatic generation of the 3-D geometry model of UAV. Three configurations of the high supersonic UAVs, including double swept wing, single swept wing and quasi-rhombus wing, are used to validate the method. The results show that accurate 3-D geometry models for all the UAV configurations can be rapidly and automatically created by the VB code. [ABSTRACT FROM AUTHOR]