An algorithm with unstructured girds is introduced in which coupling of density and temperature is considered.Static enthalpy equation is employed to construct relation between temperature correction and pressure correction.As in Rhie-Chow method,temperature and pressure corrections of grid interfaces are interpolated by static enthalpy equation and omitting neighbour temperature correction as in the velocity-pressure coupling in SIMPLEC.CGNS is taken as I/O in the in-house unstructured FVM code.For combustion simulation,Arrinius-Eddy dissipation model is employed.

An unstructured hybrid grid computational method is proposed,in which CGNS API(CFD General Notation System Application Programming Interface) is taken as pre- and post-processing and FVM(Finite Volume Method) is taken as a PDE(Partial Differential Equation) solver.In the pre-processing,the interior mesh faces and boundary mesh faces are indexed with hash table method for the requirment of the FVM solver.The results of the solver are written into original CGNS files with which the post-processing is dealt with by post-processing softwares,such as tecplot,fluent and CFX.For the solver,a cell centered FVM is applied to solve the coupled pressure and velocities with the SIMPLEC(Semi Implicit Method for Pressure Linked Equation Consistent).Two numerical examples are shown.

In this paper, some kinds of the schemes are investigated combing with the characteristics of engine shafting. Analysis result shows that the Newmard's method and the wilsion's method are more suitable for solving torsional vibration problems. A general computing programme is developed using both methods mentioned above, and two examples are presented.