Sudden Area Enlargement Pressure Recovery with Inflow Distortion

1968 ◽  
Vol 72 (687) ◽  
pp. 243-244 ◽  
Author(s):  
R. A. Tyler ◽  
R. G. Williamson
Keyword(s):  
Velocity Distribution ◽  
Pressure Recovery ◽  
Straight Pipe ◽  
Entry Velocity ◽  
Sudden Enlargement ◽  
General Velocity

Pressure recovery measurements in a straight pipe with crossflow-generated entry velocity distributions suggested substantial effects of inflow distortion on the pressure recovery downstream of a sudden enlargement in area. This note reports results of actual measurements in the same pipe equipped with entry sections of various reduced diameters providing sudden area enlargement ratios of 1.33, 1.71, 2.04, and 3.52. The results have practical bearing on the performance of settling pipes located at diffuser exits where, in general, velocity distributions are significantly non-uniform. In addition, the results provide information on the momentum content of the crossflow-generated velocity distribution.

Numerical Simulation of Stable Turbulence Generated by the Pipe Flow of Self-Regulating Air Driving Power Supply for Airflow Piezoelectric Generator

2012 ◽  
Vol 562-564 ◽  
pp. 1020-1023
Author(s):  
Jian Yu Cai ◽  
Na Lu ◽  
He Juan Chen
Keyword(s):  
Velocity Distribution ◽  
Significant Contribution ◽  
Straight Pipe ◽  
Airflow Velocity ◽  
Curved Pipe ◽  
Intake Pipe ◽  
Straight Wall ◽  
Calculation Results ◽  
Cfd Method ◽  
Geometry Characteristic

In the pan or platform carrier supply system, the intake pipe structure of the generator is very important for stability and efficiency of the airflow vibration-driving work in the small-hole aerodynamic piezoelectricity generator. Hyperbolic curved nozzle produces higher jet velocity than straight-wall nozzle. Using CFD method, contrast and analyse the annular identical-cross-section straight pipe and annular hyperbolically curved pipe, the calculation results prove the superiority of the hyperbolically curved pipe. For the geometry characteristic of the annular hyperbolic curved pipe structure, influence on the velocity distribution through varying parameters of the structure size was found out. The results show that development of the velocity distribution is directly affected by the length of straight pipe section of the pipe; better velocity distribution is obtained when length of straight pipe increases properly. On the other hand, a smaller ratio of aperture ring gap has a significant contribution to the out airflow velocity distribution.

Supersonic Diffusers With Reverse Flow Injection

1983 ◽  
Vol 105 (1) ◽  
pp. 47-52
Author(s):  
D. W. Kuntz ◽  
J. C. Dutton ◽  
S. H. White ◽  
A. L. Addy
Keyword(s):  
Flow Injection ◽  
Reverse Flow ◽  
Control Volume ◽  
Experimental Studies ◽  
High Energy ◽  
Pressure Recovery ◽  
Critical Parameters ◽  
Diffuser Flow ◽  
Sudden Enlargement ◽  
Supersonic Diffuser

In applications such as airborne high energy chemical lasers, diffuser size and weight can be critical parameters. This paper summarizes the authors’ research concerning the effects of flow injection into a supersonic diffuser in a direction opposite to that of the main flow. Experimental studies were conducted concerning the effect of diffuser performance, particularly length and pressure recovery, of this reverse flow, and a quasi-one-dimensional control volume analysis was performed to predict some of the diffuser flow properties. Single-stream, dual-stream, and sudden enlargement configurations were considered. This work has shown that a reverse flow can reduce the length of a diffuser while causing only a small decrease in overall pressure recovery.

Experimental Investigation of the Flow in Diffusers Behind an Axial Flow Compressor

1993 ◽  
Author(s):  
T. Zierer
Keyword(s):  
Velocity Distribution ◽  
Radial Velocity ◽  
Boundary Layers ◽  
Axial Flow ◽  
Side Wall ◽  
Pressure Recovery ◽  
Axial Flow Compressor ◽  
Wide Range ◽  
Inlet Conditions ◽  
Flow Compressor

The flow fields of four diffusers situated at the rear of a one-stage axial flow compressor was experimentally investigated. Through modification of the compressor operating point a wide range of variations of the side wall boundary layers and the radial velocity distribution outside of the boundary layers at diffuser inlet could be achieved. The three dimensional flow field at both diffuser inlet and outlet is analysed. Changes of inlet blockage and radial velocity distribution and their resulting effects on pressure recovery are thoroughly presented. Compared with the results of measurements at diffusers, typically with ducted flow inlet conditions, higher values of pressure recovery are observed. Established design rules, based on investigations of diffusers with carefully developed inlet flow, are checked regarding their applicability for diffusers in turbomachine environment.

Experimental Investigation of the Flow in Diffusers Behind an Axial Flow Compressor

1995 ◽  
Vol 117 (2) ◽  
pp. 231-239 ◽  
Author(s):  
T. Zierer
Keyword(s):  
Velocity Distribution ◽  
Radial Velocity ◽  
Boundary Layers ◽  
Axial Flow ◽  
Side Wall ◽  
Pressure Recovery ◽  
Axial Flow Compressor ◽  
Wide Range ◽  
Inlet Conditions ◽  
Flow Compressor

The flow fields of four diffusers situated at the rear of a one-stage axial flow compressor were experimentally investigated. Through modification of the compressor operating point, a wide range of variations of the side wall boundary layers and the radial velocity distribution outside of the boundary layers at diffuser inlet could be achieved. The three-dimensional flow field at both diffuser inlet and outlet is analyzed. Changes of inlet blockage and radial velocity distribution and their resulting effects on pressure recovery are thoroughly presented. Compared with the results of measurements at diffusers, typically with ducted flow inlet conditions, higher values of pressure recovery are observed. Established design rules, based on investigations of diffusers with carefully developed inlet flow, are checked regarding their applicability for diffusers in turbomachine environments.

scholarly journals Pressure Study on Pipe Transportation Associated with Cemented Coal Gangue Fly-Ash Backfill Slurry

2019 ◽  
Vol 9 (3) ◽  
pp. 512 ◽  
Author(s):  
Jie Yang ◽  
Baogui Yang ◽  
Mingming Yu
Keyword(s):  
Fly Ash ◽  
Velocity Distribution ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Solid Particles ◽  
Coal Gangue ◽  
General Description ◽  
Straight Pipe ◽  
Inlet Velocity ◽  
Resistance Loss

Cemented coal gangue-fly ash backfill (CGFB) slurry has commonly been used to control subsidence damage caused by underground coal mining. This paper discusses the characteristics of CGFB slurry fluidity in its pipe transportation. A general description about the components of the CGFB is provided involving the percentage of composition, particle size distribution (PSD) and rheological performance. The CGFB flow characteristics of the slurry pipeline were simulated in a straight pipe and 90° elbow pipe, respectively, combined with the pressure loss and conveying velocity distribution. With the help of the commercial computational fluid dynamic (CFD) code FLUENT, the modeling was conducted with various slurry feeding velocities. These results showed the local resistance loss in a bending pipe is significantly higher than the resistance in a straight pipe under the same conditions associated with CGFB transportation. The velocity distribution of the slurry solid particles in the slurry’s movement forward is more decentralized as the hydraulic inlet velocity increases. Based on these simulation data, a correlation was developed to predict the resistance loss of the CGFB slurry as a function of the hydraulic inlet velocity, pipe diameter and CGFB slurry rheological characteristics.

Dynamics of comets in the collapsing protosolar nebula

1999 ◽  
Vol 173 ◽  
pp. 45-50
Author(s):  
L. Neslušan
Keyword(s):  
Solar System ◽  
Velocity Distribution ◽  
Oort Cloud ◽  
Interstellar Clouds ◽  
Protosolar Nebula ◽  
Moving Bodies

AbstractComets are created in the cool, dense regions of interstellar clouds. These macroscopic bodies take place in the collapse of protostar cloud as mechanically moving bodies in contrast to the gas and miscroscopic dust holding the laws of hydrodynamics. In the presented contribution, there is given an evidence concerning the Solar system comets: if the velocity distribution of comets before the collapse was similar to that in the Oort cloud at the present, then the comets remained at large cloud-centric distances. Hence, the comets in the solar Oort cloud represent a relict of the nebular stage of the Solar system.

VELOCITY DISTRIBUTION EFFECTS IN AIR FILTER TESTING

2001 ◽  
Vol 19 (1) ◽  
pp. 1-21 ◽  
Author(s):  
FRANK CHAMBERS ◽  
ABDEL AL-SARKHI ◽  
SHENGHONG YAO
Keyword(s):  
Velocity Distribution ◽  
Air Filter
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