Fracture initiation is a key factor of hydraulic fracturing, as lack of research on fracture initiation position.The perforation geostress mechanical model of low permeability reservoir is built according to the rock mechanics, seepage mechanics, elastic-plastic mechanics, considering solid-fluid coupling and rock material nonlinearity. Adopting the transient analysis, low-permeability reservoir geostress distribution of different stages is obtained using the finite element, such as drilling - cementing - perforation –fracturing. Determine the fracture initiation position and fracture pressure combining with the rock failure criterion. Calculated on well Ao332-32, the error rate of initiation pressure between test and calculation is 3.5 percent. It is proved that the model is reasonable.

Super-critical HP steam stage static blade cascade is as the prototype blade to numerical simulations. Different swept blades are made by changing the sweep angle and sweep height in order to study the effect of swept blade on aerodynamics characteristics of turbine static cascade. The numerical simulation sweep angle are made of ±10° and 0°,swept heights are 30% blade height. The turbine aerodynamics characteristics are analyzed by NUMECA software. The numerical simulation results indicate: that aft-sweep blades negative C-type pressure distribution increase the low energy fluid centralizing in end-wall corner and the end-wall secondary flow loss, but the loss is decreased at mid-span, depending on the baseline. But fore-sweep blades C-type pressure distribution decrease the low energy fluid centralizing in endwall corner and the endwall secondary flow loss, but the loss is increased at mid-span, depending on the baseline.