Study on a Quasi-Two-Dimensional Fan Model for Variant Bypass-Ratio Condition

In order to describe how the variant BPR affects the flow performance, a qusi-2D fan model was proposed. In the model, the stage cumulative method was applied to compute axial flow and the simplified radial equilibrium equation was applied to compute radial flow, then a dual-level iteration program was proposed for the nominal performance calculation. To compute the non-nominal flow characteristics on non-nominal BPR, a triple-level iteration program with the compensation factor was proposed to obtain the radial profiles. On that basis, Blade angles were designed for this model on the design point. With the inflow deflection factor designed as 0.8 and the loss factor along blade as 0.95, the pressure ratio error is only 0.21 % and the isentropic efficiency error is 0.06 %. Simulation showed that the variant-BPR profiles and the overall characteristics of flow at fan exit or for bypass & core ducts could be well computed with much less time-consuming.

Mechanical Analysis of Flexible Pipe during Installation

Mechanical analysis of flexible pipe during installation is presented in this paper. The configuration, tension and bending moment of the flexible are important issues during the installation. A reasonable theoretical model is proposed to handle the pipe configuration and the loads during installation. Numerical iteration program for the model is developed to get the tension, bending moment distribution and the pipe configuration. Two segments which are suspended segment and seabed segment are analyzed with different calculation model for their different load conditions and boundary conditions. Finite element model is established by Abaqus to verify the results from the theoretical model. The results from theoretical are very close to the ones got from FEM. Typical installation method J-lay method is applied to perform the FEM and numerical analysis.