Analysis of Leakage Flow Through the Flank Contacts in Transition Zone in Involute External Toothed Gear Pump

2017 ◽  
Author(s):  
Vineet Sahoo ◽  
Debanshu Roy ◽  
Rathindranath Maiti
Keyword(s):  
Flow Pattern ◽  
Transition Zone ◽  
Fluid Pressure ◽  
Flow Patterns ◽  
Leakage Flow ◽  
Gear Pump ◽  
Instantaneous Flow ◽  
Analytical Results ◽  
Basic Purpose ◽  
Flow Through

The leakage past the tooth flanks of the gears in transition contacts in involute external toothed gear pump is analyzed in details using CFD in Fluent®. Analytical results support the experimentally visualized flow patterns [1]. Extending the approach of an earlier investigation [2] more rigorous analyses are carried out considering actual gear data of a pump and a full cycle of contact. However, the relieve groove and cavitation are not considered. The basic purpose is to establish the flow pattern analyses using CFD in Fluent-Ansys® environment. The beginning and the end of entrapment, squeezing of fluid, pressure build up, separation and generation of gap at the active contact and instantaneous flow through the gap are estimated meticulously.

An investigation into oil—gas two-phase leakage flow through micro gaps in oil-injected compressors

2010 ◽  
Vol 224 (4) ◽  
pp. 925-933
Author(s):  
D Xin ◽  
J Feng ◽  
X Jia ◽  
X Peng
Keyword(s):  
High Speed ◽  
Critical Pressure ◽  
Pressure Ratio ◽  
Volume Ratio ◽  
Flow Patterns ◽  
Leakage Flow ◽  
Two Phase ◽  
Gas Leakage ◽  
Flow Through ◽  
Oil Gas

This article presents the investigation on the oil—gas two-phase leakage flow through the micro gaps in oil-injected compressors and provides a new way of investigating the internal leakage process in the compressors. The oil—gas leakage rates were measured through the micro gaps of various gap sizes, the volume ratios of oil to gas, and pressure differences/ratios; and the flow patterns reflecting the flow characteristics were observed by using a high-speed video. The experimental results showed that the leakage flowrate was significantly related to the flow patterns in the gap, which were similar to those found in the existing literature and agreed well with the predicted ones by the Weber number. The gas leakage flowrate through the gap increased rapidly with the increased pressure ratio until the pressure ratio reached the critical pressure ratio, which ranged from 1.8 to 2.7. At the critical pressure ratio, the flow pattern transition from churn flow to annular flow occurred, resulting in gas leakage driven by a different sealing mechanism. As the volume ratio of oil to gas increased by 0.5 per cent, the gas leakage flowrate decreased by 77 per cent.

Gas-liquid downward flow through narrow vertical conduits: effect of angle of entry and tube-diameter on flow patterns

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Gargi Das ◽  
Subhabrata Ray ◽  
Jay Mant Jha ◽  
Amit K. Thakur ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Glass Tube ◽  
Stratified Flow ◽  
Flow Patterns ◽  
Tube Diameter ◽  
Downward Flow ◽  
Flow Rates ◽  
Included Angle ◽  
Flow Through

Abstract The present study investigates the flow pattern characteristics of air-water co-current down-flow in millichannels. The experiments have been performed in glass tube of diameter 0.0042 and 0.008 m. The fluids are injected through Y entry the included angle between the Y arms being 45°, 90°, 135°, and 180° (T Entry). The investigation reveals that the flow patterns are function of tube-diameter, and angle of fluid entry. Interestingly, stratified flow has been observed for steeper Y entry section at low liquid flow rates.

scholarly journals Influence of Hydrodynamic Conditions on the Type and Area of Occurrence of Gas–Liquid Flow Patterns in the Flow through Open–Cell Foams

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3254
Author(s):  
Roman Dyga ◽  
Małgorzata Płaczek
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Flow Patterns ◽  
Metal Foams ◽  
Hydrodynamic Characteristics ◽  
Internal Diameter ◽  
Open Cell ◽  
Flow Through ◽  
Open Cell Foams ◽  
Gas Liquid Flow

This paper reports the results of a study concerned with air−water and air−oil two–phase flow pattern analysis in the channels with open–cell metal foams. The research was conducted in a horizontal channel with an internal diameter of 0.02 m and length of 2.61 m. The analysis applied three foams with pore density equal to 20, 30 and 40 PPI (pore per inch) with porosity, typical for industrial applications, changing in the range of 92%–94%. Plug flow, slug flow, stratified flow and annular flow were observed over the ranges of gas and liquid superficial velocities of 0.031–8.840 m/s and 0.006–0.119 m/s, respectively. Churn flow, which has not yet been observed in the flow through the open–cell foams, was also recorded. The type of flow patterns is primarily affected by the hydrodynamic characteristics of the flow, including fluid properties, but not by the geometric parameters of foams. Flow patterns in the channels packed with metal foams occur in different conditions from the ones recorded for empty channels so gas−liquid flow maps developed for empty channels cannot be used to predict analyzed flows. A new gas−liquid flow pattern map for a channel packed with metal foams with the porosity of 0.92–0.94 was developed. The map is valid for liquids with a density equal to or lower than the density of water and a viscosity several times greater than that of water.

Investigation on Air-Water Two-Phase Flow in Downward Minichannel

2014 ◽  
Author(s):  
Hemant B. Mehta ◽  
Jyotirmay Banerjee
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Experimental Investigations ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

Experimental investigations are reported for gas-liquid two-phase flow through 2.15 mm circular minichannel. Influence of premixing of air-water two-phase flow through T-junction (TJ) and Y-junction (YJ) geometries is established. Vertical downward orientation (VDW) is selected for the experiments. Different flow patterns are observed and flow pattern maps are developed. The developed flow pattern maps are then compared with available literature. It is observed that inlet premixing play an important role for establishing the flow patterns and to develop flow pattern maps in VDW orientation.

A Study on the Flow Pattern Within the Centrifugal and Mixed-Flow Impellers

1971 ◽  
Author(s):  
Shinpei Mizuki ◽  
Toshimichi Sakai ◽  
Ichiro Watanabe
Keyword(s):  
Experimental Data ◽  
Flow Pattern ◽  
Surface Pressure ◽  
Flow Behavior ◽  
Inviscid Flow ◽  
Flow Patterns ◽  
Blade Surface ◽  
Mixed Flow ◽  
Analytical Results ◽  
Good Coincidence

An Investigation of the flow patterns within the centrifugal and mixed-flow impeller channel were performed. The velocity distributions within the impeller channel and blade surface pressure of the centrifugal and mixed-flow impellers were closely examined by experiment and the flow behavior within these impellers were clarified. The incompressible and inviscid flow within the impellers having straight radial blades were also derived analytically. The present authors assumed an outermost boundary of the relative eddy at the impeller exit periphery and corrected the analytical results. The corrected analytical results thus obtained showed good coincidence with the experimental data.

Film cooling characteristics on blade platform with a leakage flow through mid-passage gap

2021 ◽  
Vol 167 ◽  
pp. 120800
Author(s):  
Sehjin Park ◽  
Ho-Seong Sohn ◽  
Sangwoo Shin ◽  
Osamu Ueda ◽  
Hee Koo Moon ◽  
...  
Keyword(s):  
Film Cooling ◽  
Leakage Flow ◽  
Flow Through

scholarly journals Flow Pattern Map of Flow Boiling in a Rectangular Channel Filled with Porous Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2440
Author(s):  
Youngwoo Kim ◽  
Dae Yeon Kim ◽  
Kyung Chun Kim
Keyword(s):  
Porous Media ◽  
Flow Pattern ◽  
Flow Regime ◽  
Annular Flow ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Flow Patterns ◽  
Flow Pattern Map ◽  
Mist Flow ◽  
Churn Flow

A flow visualization study was carried out for flow boiling in a rectangular channel filled with and without metallic random porous media. Four main flow patterns are observed as intermittent slug-churn flow, churn-annular flow, annular-mist flow, and mist flow regimes. These flow patterns are clearly classified based on the high-speed images of the channel flow. The results of the flow pattern map according to the mass flow rate were presented using saturation temperatures and the materials of porous media as variables. As the saturation temperatures increased, the annular-mist flow regime occupied a larger area than the lower saturation temperatures condition. Therefore, the churn flow regime is narrower, and the slug flow more quickly turns to annular flow with the increasing vapor quality. The pattern map is not significantly affected by the materials of porous media.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

Sign in / Sign up

Export Citation Format

Share Document