摘要:

The initial‐value problem corresponding to a perturbed inviscid plane Couette flow is solved. Difficulties encountered in applying classical hydrodynamic‐stability methods are avoided by considering the initial value problem.

ISSN:0031-9171    

DOI:10.1063/1.1706010

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

The stability of an idealized atmosphere with constant shear flow and exponentially decreasing density is considered. In no case does an initial perturbation increase with time. The decrease is, in general, not faster than a small fractional power of the time.

ISSN:0031-9171    

DOI:10.1063/1.1706011

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

It is proved that the confluent hypergeometric functionWk,m(z) has no complex zeros when the indexkis real whilemis pure imaginary. Under these conditions, there is an infinite set of positive real zeros with a point of accumulation at zero. The zeros ofWk,m(z) are related to the stability of a model incompressible atmosphere, with density decreasing exponentially and horizontal wind velocity increasing linearly with height. The nonexistence of complex zeros indicates that this model atmosphere should be stable. The stability is rigorously proved in an accompanying paper by Case.

ISSN:0031-9171    

DOI:10.1063/1.1706012

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Observations are made of a density current system in which salt water flows turbulently under a pool of fresh water. The density and rate of flow of the salt water are varied, resulting in varying degrees of agitation of the interface. Measurements include the interface slope, the velocity and density profiles, and the rate of mixing. Profiles of stress and effective viscosity are developed from the observations and the equation of motion. In the zone of stable stratification the effective viscosity has a minimum equal to or greater than the molecular viscosity depending upon whether the interface is laminar or agitated. Dimensionless relationships between the observed or computed quantities and the given fluid properties and flow characteristics are investigated. The principal independent variables are a Reynolds number and a Froude number. An interfacial stress coefficient is found to depend upon both. With fair accuracy, the velocity profile can be related to the interfacial stress in a manner analogous to that for turbulent flow near a rigid boundary.

ISSN:0031-9171    

DOI:10.1063/1.1706013

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

By considering correlations between fluctuating quantities at four points in a turbulent fluid, an equation containing quadruple and quintuple correlations is obtained. The equation is made determinate by neglecting the higher‐order (quintuple) correlations. The combining of this equation with the two‐and three‐point correlation equations, and assuming a particular set of initial conditions, result in a solution which appears to represent the turbulence for times between the initial and final periods. The results reproduce most of the trends observed experimentally.

ISSN:0031-9171    

DOI:10.1063/1.1706014

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Neglecting thermal conduction and viscous dissipation, the velocity‐free equations of one‐dimensional flow are derived with the inclusion of general fluid thermodynamics. Thestrengthof finite amplitude pressure waves is introduced into the theory. This quantity is conserved if the entropy of each fluid particle remains constant with time. The growth or decay of thestrengthis examined for a perfect gas which produces entropy.

ISSN:0031-9171    

DOI:10.1063/1.1706015

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Velocity‐free equations are derived for the unsteady one‐dimensional real fluid flow of a perfect gas. These equations admit apressure‐time symmetry, astress symmetry, and adisplacement symmetry. Fundamental solutions associated with each of the three symmetries are reported.

ISSN:0031-9171    

DOI:10.1063/1.1706016

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

A theory is formulated for the displacement of a liquid from a porous system by another liquid, miscible with the first. In its most general form, the theory also may be applied to nonmiscible liquids. Differential equations are derived for the concentrations and fluxes of the two liquids as functions of time and distance in one‐dimensional flow. The equations are hyperbolic, in contrast to the equations encountered in earlier theories of miscible liquid displacement which are parabolic. The differential equations are solved for given boundary conditions. Some numerical examples illustrate the solution in the simplest case of miscible displacement.

ISSN:0031-9171    

DOI:10.1063/1.1706017

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Shock Hugoniots for liquid argon are calculated using equations‐of‐state obtained from the Monte Carlo method and the Lennard‐Jones‐Devonshire cell theory, using an experimentally determined pair potential. Agreement with presently available experimental data is poor.

ISSN:0031-9171    

DOI:10.1063/1.1706018

出版商:AIP    

年代:1960

数据来源: AIP

摘要:

Flames supported by zeroeth‐order chemical reactions have two very useful unique properties. Their characteristics are independent of diffusion, and the chemical reactions are completed at a finite point in space. These properties should make zeroeth‐order flames ideally suited to serve as ``global'' reactions for complicated flame systems involving either three‐dimensional geometry or time‐dependent phenomena. Extensive tables are given for the properties of steady‐state one‐dimensional zeroeth‐order flames. Good agreement with the numerical calculations is obtained by using a simple approximation (based upon the Adams and Wilde approach) which results in simple closed‐form expressions for the flame variables.

ISSN:0031-9171    

DOI:10.1063/1.1706019

出版商:AIP    

年代:1960

数据来源: AIP