| 1. | A new criterion for the accuracy of difference scheme at the shock is presented . it is proven that the nnd scheme meets the criterion strictly
对差分格式在激波上计算准确性的标准提出了新的看法，并证明nnd格式完全符合这个标准。 |
| 2. | Abstract : a new criterion for the accuracy of difference scheme at the shock is presented . it is proven that the nnd scheme meets the criterion strictly
文摘:对差分格式在激波上计算准确性的标准提出了新的看法，并证明nnd格式完全符合这个标准。 |
| 3. | Nnd difference scheme divergences convection item and runge - kutta scheme iterates time item . the calculated outcome agrees well with the experiment data and analytic solution
采用nnd差分格式离散对流项,时间迭代采用龙格库塔法,计算结果与实验值和解析解一致吻合。 |
| 4. | The cell - centred finite volume algorithm , nnd finite volume algorithm and ausm + finite volume algorithm are studied for solving the euler equations , their abilities for hypersonic problem are studied especially
本文分别对格心有限体积格式、 nnd有限体积格式和ausm +有限体积格式进行了研究，在求解euler方程的基础上，研究了它们对跨音速以及高超声速流场计算问题的解决能力。 |
| 5. | Through the paper " s study , the cell - centred finite volume algorithm and the 2 - order ausm + finite volume algorithm can solve the subsonic flow problem well ; the nnd finite volume algorithm and 2 - order ausm + finite volume algorithm can solve the hypersonic flow problem well
研究表明，对于跨音速问题，格心以及二阶ausm +格式解决的很好；对于高超声速问题， nnd和ausm +格式解决的很好。 |
| 6. | High - resolution nnd scheme and fully implicit dual - time stepping method were adopted in the three - dimensional vibrating cascade flow calculation . thus , the correct simulation of the shock in transonic flow and the efficiency of calculation were both taken into consideration
在三维振动叶栅流动数值模拟中，采用高分辨率tvd类型的格式和全隐式双时间方法，保证了对流动的正确模拟，准确地捕捉了跨音流动中的激波，其计算效率非常高。 |
| 7. | Non - oscillatory and non - free - parameters dissipative ( nnd ) finite difference scheme ( a total variation diminishing scheme ) with second order accuracy was adopted to solve the fluid dynamic equations , a finite rate chemical reaction model was developed to calculate ingredient producing rate , and an adi over relaxation iteration technique was used to solve the electromagnetic discretized equations
采用二阶精度nnd格式求解流体力学方程组，采用有限速率化学反应模型计算组分生成率，采用交替方向隐式( adi )超松弛迭代法求解电磁场离散方程。 |
| 8. | Then the steady and unsteady subsonic , transonic and supersonic viscous flows around airfoil and some aircraft are numerically simulated . the 3 - dimensional unsteady navier - stokes equations are solved using the implicit lu - nnd algorithm , with baldwin - lomax turbulent model . on the basis of simulating unsteady viscous flow , coupling the structure dynamics equations , the problems of static aeroelasticity and flutter are investigated for wings and elevator
在模拟非定常粘性绕流的基础上，与颤振运动方程相耦合，分别对机翼和全机流固耦合现象中颤振问题进行了研究，准确求解跨音速颤振临界速度，分析机翼和全机的从亚音速到超音速范围的颤振规律，并研究分析了机翼飞行迎角变化对颤振速度的影响。 |
| 9. | To prove the accuracy of the mach number , and the parameter homogeneity of the design nozzle " s exit , cfd calculate has carried on the design results . under the condition of supersonic and hypersonic flow , and a certain range of temperature , and mach number , the conclusion of the influence of specific heat to nozzle design is drawn
为了验证所设计的喷管出口马赫数的大小和喷管出口流场的均匀性，采用nnd格式和b l湍流模型求解雷诺平均n - s方程，对设计结果进行了cfd验算，得出了在一定温度范围内，超音速、高超声速流动的条件下，不同马赫数范围内变比热容对喷管型面和喷管出口马赫数的影响。 |
| 10. | In this paper , we analyzed and discussed the basic principle of the recently developed high order accuracy finite difference schemes ? eno schemes and weno schemes . based on 2nd order nnd schemes , we introduced a 3rd order wnnd scheme with jiang and shu ' s " weighted " idea and a tvd runge - kutta time discretization method
对于新近发展起来的eno格式和weno格式，本文分析并讨论了其基本构造原理，并且在二阶nnd格式的基础上，利用jiang和shu的加权思想和具有tvd性质的runge - kutta时间离散方法，建立了时、空三阶精度的wnnd格式。 |
