Center-Line Velocity Decay in Coaxial Free Jets

1975 ◽  
Vol 42 (2) ◽  
pp. 514-516 ◽  
Author(s):  
C. S. Lenzo ◽  
T. N. Dalai
Keyword(s):  
Center Line ◽  
Free Jets ◽  
Velocity Decay

Momentum Flux Development From Three-Dimensional Free Jets

1976 ◽  
Vol 98 (2) ◽  
pp. 256-260 ◽  
Author(s):  
J. P. Narain
Keyword(s):  
Axial Velocity ◽  
Momentum Flux ◽  
Three Dimensional ◽  
Core Region ◽  
Potential Region ◽  
Potential Core ◽  
Free Jets ◽  
Flow Development ◽  
Velocity Decay

The momentum-flux development from three-dimensional free jets has been investigated. The analysis is presented for free jets from circular, triangular, rectangular and elliptical orifices. The bluff jets, with eccentricity near unity, show the usual potential region and the axisymmetric decay region for the maximum axial velocity decay. The slender jets, with smaller than one eccentricity values, show three zones of flow development. The potential core region is followed by a characteristic decay region where velocity decay is dependent on the shape and eccentricity of the orifice. The maximum axial velocity of all slender jets finally decay axisymmetrically with increasing downstream distances.

Dynamic characteristics of supersonic turbulent free jets from four types of circular nozzles

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mingli He ◽  
Guang Zhang ◽  
Shaohua Hu ◽  
Cheng Wang
Keyword(s):  
Dynamic Characteristics ◽  
Axial Velocity ◽  
Working Pressure ◽  
Perfect Agreement ◽  
Potential Core ◽  
Free Jets ◽  
Eddy Simulation ◽  
Work Pressure ◽  
Velocity Decay ◽  
Spreading Rates

Abstract The effects of nozzle structures and working pressure on the dynamic characteristics of supersonic turbulent free jets have been investigated numerically. Four types of nozzles (namely Laval, pipe, contraction I, and contraction II, respectively) and four pressure conditions (namely K = 0.8, 1, 1.5, and 2, respectively) were considered. A Standard k-ε model was utilized for the calculation of the supersonic turbulent free jets. Validation of the model was performed on the Laval jet by comparing it with the experiment and large-eddy simulation (LES). A perfect agreement was achieved in terms of the centerline and radial axial velocity profiles. The jets issuing from the Laval and the pipe had a longer potential core and a larger centerline axial velocity with the same outlet momentum. The length of the potential core was proportional to the working pressure, but variations of the centerline axial velocity decay rate were inverse for all nozzles. The effects of nozzle structures and work pressure on the spreading rates of the jets were insignificant. No obvious change trend could be observed on the kinematic and geometric virtual origins. The study can provide references for the nozzle and working pressure selection in practical application.

Three-Dimensional Free Jets

1967 ◽  
Vol 71 (684) ◽  
pp. 858-859
Author(s):  
N. Rajaratnam ◽  
K. Subramanya
Keyword(s):  
Three Dimensional ◽  
Flow Characteristics ◽  
Maximum Velocity ◽  
Potential Core ◽  
Free Jets ◽  
Axisymmetric Jet ◽  
Plane Jets ◽  
Velocity Decay ◽  
Different Shapes ◽  
Semi Empirical

Fairly elegant semi-empirical theories are available for predicting the turbulent diffusion of axisymmetric and plane jets. However, there are relatively few investigations on the non-axisymmetric jets, herein denoted as three-dimensional jets. The extensive investigations conducted at the Polytechnic Institute of Brooklyn on three-dimensional jets have shown that the flow field is characterised by three distinct regions; the potential core, the characteristic decay (CD) region and the axisymmetric decay (AD) region. In the CD region the velocity profiles in the direction of the minor axis are similar but the maximum velocity decay curves are different for different shapes. In the AD region the flow characteristics are similar to that of an axisymmetric jet. Yevdjevich has recently conducted another investigation on rectangular jets.

Centerline Velocity Decay of Compressible Free Jets

AIAA Journal ◽  
1974 ◽  
Vol 12 (4) ◽  
pp. 417-418 ◽  
Author(s):  
PETER O. WITZE
Keyword(s):  
Centerline Velocity ◽  
Free Jets ◽  
Velocity Decay

Finite Element Modeling for Steel Cord Analysis in Radial Tires

2013 ◽  
Vol 41 (1) ◽  
pp. 60-79 ◽  
Author(s):  
Wei Yintao ◽  
Luo Yiwen ◽  
Miao Yiming ◽  
Chai Delong ◽  
Feng Xijin
Keyword(s):  
Finite Element ◽  
High Efficiency ◽  
Force Measurement ◽  
Three Dimensional ◽  
Local Stress ◽  
Tension Force ◽  
Center Line ◽  
Element Analysis ◽  
Design Variables ◽  
Steel Cord

ABSTRACT: This article focuses on steel cord deformation and force investigation within heavy-duty radial tires. Typical bending deformation and tension force distributions of steel reinforcement within a truck bus radial (TBR) tire have been obtained, and they provide useful input for the local scale modeling of the steel cord. The three-dimensional carpet plots of the cord force distribution within a TBR tire are presented. The carcass-bending curvature is derived from the deformation of the carcass center line. A high-efficiency modeling approach for layered multistrand cord structures has been developed that uses cord design variables such as lay angle, lay length, and radius of the strand center line as input. Several types of steel cord have been modeled using the developed method as an example. The pure tension for two cords and the combined tension bending under various loading conditions relevant to tire deformation have been simulated by a finite element analysis (FEA). Good agreement has been found between experimental and FEA-determined tension force-displacement curves, and the characteristic structural and plastic deformation phases have been revealed by the FE simulation. Furthermore, some interesting local stress and deformation patterns under combined tension and bending are found that have not been previously reported. In addition, an experimental cord force measurement approach is included in this article.

Energy Propagation in Heated Turbulent Free Jets

1987 ◽  
Author(s):  
L. Gbahoué ◽  
S. Lecume ◽  
J.L. Carreau ◽  
Ph. Hobbes ◽  
F. Roger
Keyword(s):  
Energy Propagation ◽  
Free Jets

Spray generation from free and half-free jets

2000 ◽  
Author(s):  
T. Sarpkaya ◽  
R. Vaidyanathan
Keyword(s):  
Free Jets
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