Static pressure distribution in the free turbulent jet

1957 ◽  
Vol 3 (1) ◽  
pp. 1-16 ◽  
Author(s):  
David R. Miller ◽  
Edward W. Comings
Keyword(s):  
Static Pressure ◽  
Longitudinal Velocity ◽  
Fluid Motion ◽  
Mean Velocity ◽  
Free Jet ◽  
Static Pressure Distribution ◽  
Two Dimensional Flow ◽  
The Common ◽  
Jet Theory ◽  
Made In

Measurements of mean velocity, turbulent stress and static pressure were made in the mixing region of a jet of air issuing from a slot nozzle into still air. The velocity was low and the two-dimensional flow was effectively incompressible. The results are examined in terms of the unsimplified equations of fluid motion, and comparisons are drawn with the common assumptions and simplifications of free jet theory. Appreciable deviations from isobaric conditions exist and the deviations are closely related to the local turbulent stresses. Negative static pressures were encountered everywhere in the mixing field except in the potential wedge region immediately adjacent to the nozzle. Lateral profiles of mean longitudinal velocity conformed closely to an error curve at all stations further than 7 slot widths from the nozzle mouth. An asymptotic approach to complete self-preservation of the flow was observed.

scholarly journals ANALYSIS OF TWO-DIMENSIONAL FLOW IN DUCTS WITH CIRCULAR SAW GITT FORMULATION IN PRIMITIVE VARIABLES

2011 ◽  
Vol 10 (1-2) ◽  
pp. 73
Author(s):  
J. H. Andrade ◽  
C. A. C. Santos ◽  
A. W. A. Cavalcante ◽  
M. A. Rocha
Keyword(s):  
Velocity Profile ◽  
Integral Transform ◽  
Longitudinal Velocity ◽  
Model Fitting ◽  
Axial Direction ◽  
Two Dimensional ◽  
Mean Velocity ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Primitive Variables

In this paper the Generalized Integral Transform Technique is employed to produce hybrid solutions for the velocity and pressure fields of a newtonian fluid in two dimensional flow. The problem is formulated by using primitive variables and the necessary mathematical manipulations were used to obtain the Poisson equation for the pressure field. The momentum equations in the axial direction of flow and Poisson are transformed to remove the transversal dependency. The resulting transformed fields are solved with the IMSL numerical subroutine, DBVPFD. The obtained results for the longitudinal velocity profile at the center of the channel are compared with the available data in the open literature for validation and model fitting. Even so, studies are carried out about the convergence of the solution for the velocity profile in the centerline as well as testing different values of the scale factor of axial coordinate for the choice of a factor which can fit perfectly for comparison with available data. Interest practical datas such as: friction factor and mean velocity are obtained along the duct for a entry condition into the parallel flow channel (v = 0).

Some Aspects of Three-Dimensional Cavity Flow

1957 ◽  
Vol 61 (557) ◽  
pp. 345-352
Author(s):  
A. J. Taylor-Russell
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Cavity Flow ◽  
Wake Flow ◽  
Flat Plates ◽  
Mean Velocity ◽  
Wake Flows ◽  
Low Aspect Ratio ◽  
Recirculatory Flow ◽  
Made In

SummarySome experiments concerned with the wake flows of a number of flat plates of low aspect ratio (Fail, Owen and Eyre) have suggested that for large angles of inclination to the undisturbed stream the wake includes a region of recirculation. The present observations include a detailed study of this region, with particular reference to the wake produced by an equilateral triangular plate, and an attempt is made to explain why the recirculatory flow is found only at angles of incidence greater than 35°. The data includes some wind tunnel measurements of force coefficients, static pressure and mean velocity, and observations of the wake flow made in a smoke tunnel and in a water tunnel.

Experimental Investigation of Flow Resistance and Wall Shear Stress in the Interior Subchannel of a Triangular Array of Parallel Rods

1979 ◽  
Vol 101 (4) ◽  
pp. 429-434 ◽  
Author(s):  
M. Fakory ◽  
N. Todreas
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Friction Factor ◽  
Static Pressure ◽  
Reynolds Numbers ◽  
Triangular Array ◽  
Flow Area ◽  
Static Pressure Distribution ◽  
The Common ◽  
Wall Shear

A simulated model of a triangular array of rods with pitch to diameter ratio of 1.1 with air flow was used to study the hydraulic parameters of the liquid metal fast breeder reactor (LMFBR) fuel geometry. The wall shear stress distribution, static pressure distribution, turbulence intensity, and friction factor were measured in the central subchannel from Reynolds numbers of 4 × 103 to 36 × 103. Our results show that the maximum wall shear stress occurs at the largest flow area, the static pressure is not uniform around the rod periphery, there is no detectable presence of secondary flow from the wall shear stress measurements, and the friction factor derived from the measured wall shear stress is less than the common friction factor derived from pressure drop measurement.

The Flow Region Near the Nozzle in Double Concentric Jets

1964 ◽  
Vol 86 (4) ◽  
pp. 797-804 ◽  
Author(s):  
N. A. Chigier ◽  
J. M. Bee´r
Keyword(s):  
Static Pressure ◽  
Flow Region ◽  
Mean Velocity ◽  
Pressure Distributions ◽  
Air Jet ◽  
The Mean ◽  
Annular Jets ◽  
Made In

The type of double concentric jets considered in this paper consists of a central round air jet surrounded by an annular air jet issuing into stagnant air surroundings. Detailed measurements of the mean velocity and static-pressure distributions have been made in the region close to the exit of the nozzles and the effect of varying the ratio of the velocities in the central and annular jets has been examined.

Mean velocity and static pressure distributions in a three-dimensional turbulent free jet

AIAA Journal ◽  
1985 ◽  
Vol 23 (6) ◽  
pp. 971-973 ◽  
Author(s):  
W. R. Quinn ◽  
A. Pollard ◽  
G. F. Marsters
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Mean Velocity ◽  
Free Jet ◽  
Pressure Distributions

Velocity and Static-Pressure Distributions in Swirling Air Jets Issuing From Annular and Divergent Nozzles

1964 ◽  
Vol 86 (4) ◽  
pp. 788-796 ◽  
Author(s):  
N. A. Chigier ◽  
J. M. Bee´r
Keyword(s):  
Static Pressure ◽  
Reverse Flow ◽  
Ring Vortex ◽  
Pressure Gradients ◽  
Mean Velocity ◽  
Air Jets ◽  
Pressure Distributions ◽  
Angular Momenta ◽  
Set Up ◽  
Made In

Mean-velocity and static-pressure measurements have been made in a series of swirling air jets issuing from annular and divergent nozzles into stagnant-air surroundings. Swirl was generated by introducing varying proportions of air through tangential ports while the remainder of the air was introduced axially. A region of subatmospheric pressure is set up in the central region of the jets and as soon as the pressure gradients on the axis exceed a certain critical value, reverse flow is set up with an associated internal ring vortex. With increasing degrees of swirl, the angle of spread of the jets is increased and, correspondingly, the decay of the maximum values of axial, tangential, and radial components of velocity along the lengths of the jets is faster. The integrated axial fluxes of linear and angular momenta were shown to be conserved along the length of the jets.

An Overview of Dementias

2012 ◽  
Vol 21 (3) ◽  
pp. 75-84
Author(s):  
Venkata Vijaya K. Dalai ◽  
Jason E. Childress ◽  
Paul E Schulz
Keyword(s):  
Clinical Presentation ◽  
Treatment Options ◽  
Current Treatment ◽  
Great Variability ◽  
Health Concern ◽  
Public Health Concern ◽  
Life Threatening ◽  
The Common ◽  
Neurodegenerative Dementias ◽  
Made In

Dementia is a major public health concern that afflicts an estimated 24.3 million people worldwide. Great strides are being made in order to better diagnose, prevent, and treat these disorders. Dementia is associated with multiple complications, some of which can be life-threatening, such as dysphagia. There is great variability between dementias in terms of when dysphagia and other swallowing disorders occur. In order to prepare the reader for the other articles in this publication discussing swallowing issues in depth, the authors of this article will provide a brief overview of the prevalence, risk factors, pathogenesis, clinical presentation, diagnosis, current treatment options, and implications for eating for the common forms of neurodegenerative dementias.

Cuckoo chicks evicting their nest mates: coincidental observations by Edward Jenner in England and Antoine Joseph Lottinger in France

2011 ◽  
Vol 38 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Spencer G. Sealy ◽  
Mélanie F. Guigueno
Keyword(s):  
Royal Society ◽  
Cuculus Canorus ◽  
Common Cuckoo ◽  
Cuckoo Chick ◽  
The Common ◽  
Made In ◽  
Royal Society Of London

For centuries, naturalists were aware that soon after hatching the common cuckoo (Cuculus canorus) chick became the sole occupant of the fosterer's nest. Most naturalists thought the adult cuckoo returned to the nest and removed or ate the fosterer's eggs and young, or the cuckoo chick crowded its nest mates out of the nest. Edward Jenner published the first description of cuckoo chicks evicting eggs and young over the side of the nest. Jenner's observations, made in England in 1786 and 1787, were published by the Royal Society of London in 1788. Four years before Jenner's observations, in 1782, Antoine Joseph Lottinger recorded eviction behaviour in France and published his observations in Histoire du coucou d'Europe, in 1795. The importance of Lottinger's and Jenner's observations is considered together.

Mean velocity and static pressure distributions of a circular jet

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 196-197
Author(s):  
M. T. Islam ◽  
M. A. T. Ali
Keyword(s):  
Static Pressure ◽  
Mean Velocity ◽  
Pressure Distributions

On the criteria for reverse transition in a two-dimensional boundary layer flow

1969 ◽  
Vol 35 (2) ◽  
pp. 225-241 ◽  
Author(s):  
M. A. Badri Narayanan ◽  
V. Ramjee
Keyword(s):  
Longitudinal Velocity ◽  
Outer Region ◽  
Transition Process ◽  
Velocity Profiles ◽  
Wall Region ◽  
Two Dimensional ◽  
Mean Velocity ◽  
Law Of The Wall ◽  
Reverse Transition ◽  
Turbulence Decay

Experiments on reverse transition were conducted in two-dimensional accelerated incompressible turbulent boundary layers. Mean velocity profiles, longitudinal velocity fluctuations $\tilde{u}^{\prime}(=(\overline{u^{\prime 2}})^{\frac{1}{2}})$ and the wall-shearing stress (TW) were measured. The mean velocity profiles show that the wall region adjusts itself to laminar conditions earlier than the outer region. During the reverse transition process, increases in the shape parameter (H) are accompanied by a decrease in the skin friction coefficient (Cf). Profiles of turbulent intensity (u’2) exhibit near similarity in the turbulence decay region. The breakdown of the law of the wall is characterized by the parameter \[ \Delta_p (=\nu[dP/dx]/\rho U^{*3}) = - 0.02, \] where U* is the friction velocity. Downstream of this region the decay of $\tilde{u}^{\prime}$ fluctuations occurred when the momentum thickness Reynolds number (R) decreased roughly below 400.

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