力学学报

1991, 23(6) doi: 10.6052/0459-1879-1991-6-1995-903

PDF

AN EFFICIENT ALGORITHM FOR HYPERSONIC VISCOUS FLOWS

The CSCM-S algorithm proposed by Lombard et al is very attractivefor multidimensional Euler and Navier-Stokes equations. However, it is not economical due to the use of global sweeps in the whole computational domain. In this paper we suggest a modified strategy, which combines a single-marching technique for supersonic dominated region with a multi-sweep procedure for pure subsonic and complex flowfield. The new algorithm may save significantly CPU time and is more suitable for engineering applications.

1991, 23(6): 641-649. doi: 10.6052/0459-1879-1991-6-1995-887

PDF

THE GENERAL FORM OF TURBULENT WALL-FUNCTIONS

The general form of turbulent wall-functions is presented. It is applicableto the turbulent computation with wall injtction or suction, The widely used turbulent wall-functions for turbulent computation without injection or suction are the special case of the general form of turbulent wall-functions.

1991, 23(6): 650-657. doi: 10.6052/0459-1879-1991-6-1995-888

PDF

THE THERMOCAPILLARY CONVECTION IN THE LIQUID BRIDGE WITH DIFFERENT PRANDTL NUMBER

Due to the progresses of space technology, the manufacture of high quality materials such as the semi-conductors or metal (Pr<<1) in space is coming true. It is difficult to observe the flow structure and temperature distribution in the liquid bridge of opaque molten semi-conductor or metal. Therefore, in present time, the experiments of thermocapil-lary convection are mainly conducted in the liquid bridge with transparent medium (Pr>1) such as silicon oil. The purpose of this paper is to study whether the ...

1991, 23(6): 658-665. doi: 10.6052/0459-1879-1991-6-1995-889

PDF

NON-PROPAGATING SOLITARY WAVES WITH THE CONSIDERATION OF SURFACE TENSION

In this paper, the governing equations for the non-propagating solitarywaves, similar to the cubic Schrodinger equation are derived by the multiple scale method with the consideration of surface tension. The non-propagating solitary waves solution is given. It is explained by the capillary-gravity wave theory that the crests are sharpened and the troughs are plattened in the transverse harmonic of the non-propagating solitary waves. On σ-kh plane, two parameter regions are gotten in which the non-propagatin...

1991, 23(6): 666-673. doi: 10.6052/0459-1879-1991-6-1995-890

PDF

THE DISTRIBUTION LAW OF AERODYNAMIC FORCE AND MOMENT AND THE GENERALIZED KUTTA-JOUKOWSKI THEOREM

A concept of 'kinetic vorticity' has been introduced and the general formulas of aerodynamic force and moment are developed-through a rigorous analysis of the compressible viscous flow equations. The force and moment exerted on the solid body are expressed as the rate of change of the first-and second-order kinetic vorticity moments, respectively. A distribution law of aerodynamic force and moment is further developed from the genera) formulas cooperating with the Navier-Stokes equation. Each of the explici...

1991, 23(6): 674-684. doi: 10.6052/0459-1879-1991-6-1995-891

PDF

SCATTERING OF ELASTIC WAVES BY MULTIPLE NON-COP-LANAR PENNY-SHAPED CRACKS IN A LAYERED MEDIUM

Based on the reference [1] , using Hankel integral transform, a rigorous theory of the scattering of elastic waves by multiple non-coplanar penny-shaped cracks in a layered medium is presented in this paper. From the obtained results, it is shown that the problem is astonishingly similar in form to the case of Griffith cracks [1] , but there exts inherent differences between the two cases.

1991, 23(6): 685-699. doi: 10.6052/0459-1879-1991-6-1995-892

PDF

THE STRESS ANALYSIS OF CYLINDRICAL SHELLS WITH CUTOUTS

In this paper we deal with the analysis of stress distributions aroundcircular cutouts in cylindrical shells. Because of the complicated boundary shapes in this type of problems, it is difficult to solve the well known Morley's equation. Based on the error analysis we modified the Morley's equation, and furthermore got a general solution of the modified Morley's tquation which is suitable for the analysis of cutout problems. We took the problems of cylindrical shells under the action of axial tension and in...

1991, 23(6): 700-705. doi: 10.6052/0459-1879-1991-6-1995-893

PDF

MAGNETOELASTIC BUCKLING OF A CIRCULAR PLANAR COIL

The condition of magnetoelastic buckling is presented for a circularplanar coil in a circum ferential and transverse magnetic field. The results of F.C. Moon are extended.

1991, 23(6): 706-711. doi: 10.6052/0459-1879-1991-6-1995-894

PDF

THE ABSTRACT REPRESENTATION OF RATES OF STRETCH TENSORS

The present paper provides the representation for time derivatives U andV of right-and left stretch tensors U and V by means of principal-axis intrinsic method. The so-called "separation technique" introduced in this paper enables to use effectively standard representations of tensor functions. The expression for V is new. Two new relations between U and V are given as well.

1991, 23(6): 712-720. doi: 10.6052/0459-1879-1991-6-1995-895

PDF

EXPERIMENTAL STUDY OF LAMINAR FLOW AND INSTABILITY MECHANISM OF ROUND JET WITH LOW SPEED

The laminar flow and instability mechanism of a round jet are investigated by visualization methods of dye and particle tracers. The toroidal backflow in a low speed round jet issuing from a nozzle was observed successfully for the first time. The flow visualization photographs demonstrated both the evolution of jet flow and effect on it of bottom boundary of the test vessel. It was found that the axisymmetric disturbance occurring in the real jet and its instability process are corresponding just right to ...

1991, 23(6): 721-726. doi: 10.6052/0459-1879-1991-6-1995-896

PDF

INVESTIGATION FOR FLOW ENHANCMENT PHENOMENON OF DILATANT FLOW IN A NARROW SLIT

LDV is used to measure the velocity profiles and near wall velocities fora dilatant flow-gel 107 solution flow in a slit. After some modification in the Poiseuille flow formulas has been made for side-wall effect correction, the results of LDV measurements combined with bulk parameters are utilized to analyse the enhancement evidence and quantities of the flow, The feasibility of using LDV to investigate flow enhancement phenomenon in detail is demonstrated

1991, 23(6): 727-732. doi: 10.6052/0459-1879-1991-6-1995-897

PDF

INVESTIGATION OF NATURAL CONVECTION PHENOMENA FROM A HORIZONTAL HEATED TUBE USING ESPI

The natural convection phenomena from a horizontal heated tube is investigated using Vintens ESPI, Video holographic interferometry and holography. Three different optical arrangements and the principle of gas temperature measurement are described. The experimental results obtained from the above techniques are compared with those from thermocouples. The comparison shows that they are consistent with each other. The sources of error which may affect the measurement are discussed and estimated qualitatively.

1991, 23(6): 733-737. doi: 10.6052/0459-1879-1991-6-1995-898

PDF

THE PARAMETRICAL EXCITATION OF COLLAPSIBLE LATEX TUBE WITH CHANGEABLE RICIDITY

If the transmural pressure of a latex tube containing pulsatile flow is negative, the tube will collapse with its cross-sectional area and moment of inertia decreasing. At first, this paper derived the governing equation of the related problem, that is, the Ma bieu equation with damping and then solved to by the method of strained coordinates in the theory of singular perturbation. It is verified that the periodic change of cross-sectional area and moment of inertia enforces the excitation of the pulsatile ...

1991, 23(6): 738-742. doi: 10.6052/0459-1879-1991-6-1995-899

PDF

AN ANALYSIS OF THE SHAKEDOWN PROBLEM OF ELASTO- PLASTIC STRUCTURES UNDER QUASI-STATIC LOADING BY THE PERTURBATION METHOD

In this paper, the shakedown problem is dealt with of elastoplastic structures subjected to the quasi-statically varying loads within a given domain. The work-hardening yield surface of the material is assumed to be piecewise linear. A general inequality is presented, according to which, the generalized Melan's shakedown criterion as well as bounds on displacement and plastic strain are derived. Moreover, applications of the derived result are illustrated by a simple example.

1991, 23(6): 743-749. doi: 10.6052/0459-1879-1991-6-1995-900

PDF

INTERACTION OF ANTIPLANE SHEAR WAVE WITH PERIO DICALLY ARRAYED INTERFACE CRACKS

In this paper, the interaction of antiplane shear waves with periodicallyarrayed cracks at the interface of two bonded dissimilar elastic half-space is considered. By using the finite Fourier transform techniques, the solution of the mixed boundary value problem for a typical strip is reduced to a set of singular integral equation with a singular kernel of ctgπ/L(u-x), where L is the width of the periodical strip. By means of Chebyshev polynomial, theequation is solved numerically. And finally, the variatio...

1991, 23(6): 750-754. doi: 10.6052/0459-1879-1991-6-1995-901

PDF

THE TRANSFORMATION OF THE PAPKOVICH-NEUBER (P-N) GENERAL SOLUTION AND OTHERS

In this note the completeness of P-N solution is proved. The proof is basedupon constructing the transformation of the P-N solution. It is shown that the theorem of E-S convex region can be automatically derived by using any harmonic function which is included in the transformation and represents zero displacement field. In addition, the general solution of plane strain problems can also be obtained directly from the same transformation

1991, 23(6): 755-758. doi: 10.6052/0459-1879-1991-6-1995-902

PDF

1991 Vol. 23, No. 6

NoticeMORE+

Exquisite ArticlesMORE+

Download Center

Author Center