Effect of rotational direction of triple-swirler on cold flow characteristics of a model combustor

2016 ◽  
Vol 231 (5) ◽  
pp. 918-930 ◽  
Author(s):  
Ziqiang Zhao ◽  
Xiaomin He ◽  
Guoyu Ding ◽  
Mingyu Li ◽  
Ping Jiang ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Atmospheric Condition ◽  
Experimental Investigations ◽  
Image Velocimetry ◽  
Mass Proportion ◽  
Rotational Direction ◽  
High Temperature Rise

Triple-swirler plays an important role for aero-engine combustors to achieve high temperature rise. In this paper, experimental investigations were carried out to explore the effect of triple-swirler rotational direction on swirling flow field in atmospheric condition. Two-dimensional-planar particle image velocimetry measurements show that the central toroidal recirculation zone (CTRZ) formation is significantly affected by the swirler rotational direction combinations: an obvious CTRZ can be formed by the triple-swirler with co-rotating intermediate swirler and outer swirler, while a much smaller CTRZ was obtained by the triple-swirler with a counter-rotating intermediate and outer swirler. Furthermore, the swirl level of the mixed flow is significantly affected by the rotational direction combination, and the integrated swirl numbers were calculated to help evaluating the swirl level generated by triple-swirlers. The rotational direction combination plays a key role on the tangential velocity distribution. The tangential velocity distribution is not only closely related to rotational direction, but also the swirl number combination and mass proportion of each swirler in a triple-swirler.

Effect of inlet port on the flow in the cylinder of an internal combustion engine

2006 ◽  
Vol 220 (1) ◽  
pp. 73-82 ◽  
Author(s):  
A Yasar ◽  
B Sahin ◽  
H Akilli ◽  
K Aydin
Keyword(s):  
Particle Image Velocimetry ◽  
Velocity Distribution ◽  
Particle Image ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Intake Port ◽  
Intake Valve ◽  
Piv Technique ◽  
Image Velocimetry ◽  
Image Density

In this study, the characteristics of flow emerging from the inlet of the intake port in the cylinder were investigated experimentally. A particle image velocimetry (PIV) technique was used to measure the velocity distribution in order to observe and analyse the flow behaviour. High-image-density PIV provided acquisition of patterns of instantaneous and averaged vorticity and velocity, revealing the detail of the flow characteristics in the cylinder cavity. With this measuring technique, it is possible to study the effect of intake valve geometry on the flow behaviours. The results showed that the flow structure changed substantially along the cylinder stroke due to the geometry of the intake valve port.

CFD Analysis of Circle Grid Fractal Plate Thickness on Turbulent Swirling Flow

2013 ◽  
Vol 465-466 ◽  
pp. 109-113 ◽  
Author(s):  
Bukhari Manshoor ◽  
Izzuddin Zaman ◽  
Mohamad Jaat ◽  
Amir Khalid
Keyword(s):  
Pressure Drop ◽  
Swirling Flow ◽  
Plate Thickness ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Turbulent Model ◽  
Swirl Angle ◽  
Ansys Cfx ◽  
Flow Through ◽  
Different Thickness

In this paper, steady state, incompressible, swirling turbulent flow through circle grid fractal plate has been simulated. The aim of the simulation is to investigate an effect of the circle grid fractal plate thickness in order to reduce swirling due to swirl disturbance in pipe flow. The simulation and analysis were carried out using finite volume CFD solver ANSYS CFX. Three different thickness of fractal plate were used in the simulation work with the thickness of 1 mm, 3 mm and 6 mm. The simulation results were compared with the pressure drop correlation of BS EN ISO 5167-2:2003 and turbulent model used, standard k-ε model gave the best agreement with the ISO pressure drop correlation. The effects of circle grid fractal plate thickness on the flow characteristics which are swirl angle and tangential velocity have been investigated as well.

Streamwise Development of Co-Rotating, Paired Vortices Created by Tangential Injection

2003 ◽  
Author(s):  
Mary V. Holloway ◽  
Heather L. McClusky ◽  
Donald E. Beasley
Keyword(s):  
Swirling Flow ◽  
Tangential Velocity ◽  
Reynolds Numbers ◽  
Velocity Fields ◽  
Flow Structures ◽  
Lateral Velocity ◽  
Swirl Generator ◽  
Swirl Chamber ◽  
Image Velocimetry ◽  
Downstream Development

The present experimental study investigates the interaction and downstream development of two localized swirling flow structures created using a tangential injection method. A swirl generator is placed at the inlet of a 52.1 mm diameter pipe. The swirl generator consists of two swirl chambers with inner diameters of 23.8 mm. Each swirl chamber has a design swirl number of 7.14. Water is injected into each swirl chamber by two tangential injection ports. The injection ports are tangent to the swirl chamber and perpendicular to the axis of the pipe. The two co-rotating vortices created in the swirl generator interact freely within the pipe downstream of the swirl generator. The objective of the present study is to document the interaction between the two vortices and the downstream development of the flow. Lateral velocity fields are obtained using particle image velocimetry (PIV). Time-averaged lateral velocity fields and tangential velocity profiles are presented for several axial locations downstream of the swirl generator. Reynolds numbers of 11,000 and 17,000 are investigated. Results document the streamwise development and interaction between the two co-rotating vortices created by tangential injection. As the two swirling structures develop in the streamwise direction, three different types of flow patterns are identified. The first consists of two distinct swirling flow structures. Further downstream of the swirl chamber, the two swirling structures merge and form a single swirling flow structure with an elliptic core. In the third flow pattern, the center core of the swirling flow has a circular shape.

Numerical Investigation Into Fully and Partially Wetted Disk Geometries With Relevance to Intershaft Hydraulic Seals

2020 ◽  
Author(s):  
Achinie Warusevitane ◽  
Kathy Johnson ◽  
Stephen Ambrose ◽  
Mike Walsh ◽  
Colin Young
Keyword(s):  
Fluid Dynamic ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Rotating Disk ◽  
Radial Pressure ◽  
Experimental Investigations ◽  
Published Data ◽  
Cfd Modelling ◽  
Validation Data ◽  
Rotating Shafts

Abstract Civil aero-engines contain two or three shafts that are supported by bearings. Seals are required both between pairs of rotating shafts and between static elements and shafts. Seals located between two co/contra rotating shafts within the bearing chamber are known as intershaft seals and are typically classified as either hydraulic or oil backed. This paper focuses on research relevant to intershaft hydraulic seals. A hydraulic seal is formed by a seal fin on the inner shaft immersed in an annulus of oil in the outer shaft where the oil in the annulus is centrifuged outwards by the radial pressure gradient. Once formed a hydraulic seal does not allow air to flow across the seal and any pressure difference across the seal creates different oil levels either side of the fin. Despite their reliable operation with zero leakage, the application of hydraulic seals is restricted due to temperature limitations, oil degradation and coking. Research and development of the next generation of hydraulic seals needs to focus on addressing these issues so that the seals can be utilized in hotter zones in future engines. Understanding of the detailed fluid dynamic behaviour during hydraulic seal operation is relatively limited with very little published data. There is an acknowledged need for improved knowledge and this is the context for the current study. The ability to accurately computationally model hydraulic seals is highly desirable. Prior experimental and analytical investigations into fully and partially wetted rotating disks have been used to aid understanding of the performance and flow characteristics of hydraulic seals as there are many geometric and operational similarities. These fundamental experimental investigations in the literature provide validation data that allows the authors to establish a CFD modelling methodology. This paper initially compares the flow characteristics of a fully wetted rotating disk against experimental results available in literature including the radial and tangential velocity components. This paper subsequently investigates the flow characteristics of a partially wetted disk by examining the effect on the angular velocity of the fluid core with varying engagement and spacing ratios for two flow regimes.

Particle image velocimetry studies on the swirling flow structure in the vortex gripper

2012 ◽  
Vol 227 (9) ◽  
pp. 1927-1937 ◽  
Author(s):  
Qiong Wu ◽  
Qian Ye ◽  
GuoXiang Meng
Keyword(s):  
Reynolds Number ◽  
Particle Image Velocimetry ◽  
Turbulent Flow ◽  
Flow Structure ◽  
Particle Image ◽  
Swirling Flow ◽  
Tangential Velocity ◽  
Internal Flow ◽  
Dynamics Simulation ◽  
Image Velocimetry

In this article, particle image velocimetry was used to measure the two-dimensional flow field for vortex gripper. The vortex gripper was divided into two parts for respective research, including vortex cup and the gas film gap. In the part of vortex cup, the tangential velocity increases gradually, and the velocity decreases intensely in the vicinity of the vortex cup’s wall after it reaches maximum. In addition, the velocity decreases gradually with the increase of the gas film gap. In the part of gas film gap, the tangential velocity increases to maximum along the radial direction first; after the air flows into the gas film gap due to the viscous impedance, it decreases gradually. When the gas film gap’s thickness is smaller, the velocity almost decreases to zero at the external edge of the skirt. However, when the gas film gap increases to a certain thickness, the velocity does not decrease to zero, and the flow air still keeps a certain speed out of it. The velocity decreases gradually with the increase of the gas film gap. The radial velocity in the vortex cup and the gas film gap is of very small order of magnitude comparing with the average velocity and tangential velocity. The analysis of the Reynolds number shows that the flow in the vortex cup is the turbulent flow, and at the part of the gas film gap, the Reynolds number increases with the increase of the gas film gap, and the flow changes from the laminar flow to the turbulent flow. Through the particle image velocimetry experiment, the vortex gripper’s internal flow structure is studied. It is the theory support of the computational fluid dynamics simulation study for vortex gripper and the structure optimization in the future work.

scholarly journals Liquid–Solid Flow Characteristics in Vertical Swirling Hydraulic Transportation with Tangential Jet Inlet

2021 ◽  
Vol 9 (10) ◽  
pp. 1091
Author(s):  
Jiyang Qi ◽  
Jie Yin ◽  
Fei Yan ◽  
Ping Liu ◽  
Tieli Wang ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Drag Force ◽  
Particle Concentration ◽  
Swirling Flow ◽  
Fluid Velocity ◽  
Flow Characteristics ◽  
Spherical Particles ◽  
Transport Systems ◽  
Solid Flow ◽  
Tangential Flow

In order to improve the efficiency and safety of vertical hydraulic transport systems for non-spherical particles, a new pipeline transport system with a tangential jet inlet is adopted in this study, and a modified non-spherical drag coefficient model is used to analyze the liquid–solid flow characteristics based on the CFD-DEM (Computational Fluid Dynamics-Discrete Element Method)coupling method. The focus of the study is on the influence of different tangential flow proportions in terms of the velocity distribution, the vorticity, the total pressure, the concentration and drag force of particles of various shapes. The conveying efficiency is measured according to the fluid velocity distribution and the particle concentration, and the safety of conveying is evaluated according to the flow structure and drag force of the particles. The result shows that the velocity of the swirling pipes is significantly higher than the straight pipe. With the increase of the tangential flow proportion, the swirling number and the vorticity magnitude increase, and the vortex core is broken and merged more quickly. Furthermore, the concentration gap and axial drag force gap between particles of various shapes are reduced with the effect of swirling flow, the particle concentration increases, and the particles of each component are uniformly mixed and transported.

COMPUTATIONAL AND EXPERIMENTAL INVESTIGATIONS OF FLOW CHARACTERISTICS IN A CURVILINEAR INLET CHANNEL

2017 ◽  
Vol 48 (4) ◽  
pp. 357-362
Author(s):  
Denis Vyacheslavovich Anokhin ◽  
Evgenia Sergeevna Dyagileva ◽  
Oleg Petrovich Minin ◽  
Dmitrii Aleksandrovich Olishevskii ◽  
Sergei Grigorievich Shevel'kov
Keyword(s):  
Flow Characteristics ◽  
Experimental Investigations ◽  
Inlet Channel

Experimental investigation of the influence of the hydraulic performance of an axial blood pump on intraventricular blood flow

2021 ◽  
pp. 039139882110130
Author(s):  
Guang-Mao Liu ◽  
Fu-Qing Jiang ◽  
Xiao-Han Yang ◽  
Run-Jie Wei ◽  
Sheng-Shou Hu
Keyword(s):  
Blood Flow ◽  
Particle Image ◽  
Swirling Flow ◽  
Blood Stasis ◽  
Systemic Circulation ◽  
Operating Conditions ◽  
Blood Pump ◽  
Image Velocimetry ◽  
Ct Data

Blood flow inside the left ventricle (LV) is a concern for blood pump use and contributes to ventricle suction and thromboembolic events. However, few studies have examined blood flow inside the LV after a blood pump was implanted. In this study, in vitro experiments were conducted to emulate the intraventricular blood flow, such as blood flow velocity, the distribution of streamlines, vorticity and the standard deviation of velocity inside the LV during axial blood pump support. A silicone LV reconstructed from computerized tomography (CT) data of a heart failure patient was incorporated into a mock circulatory loop (MCL) to simulate human systemic circulation. Then, the blood flow inside the ventricle was examined by particle image velocimetry (PIV) equipment. The results showed that the operating conditions of the axial blood pump influenced flow patterns within the LV and areas of potential blood stasis, and the intraventricular swirling flow was altered with blood pump support. The presence of vorticity in the LV from the thoracic aorta to the heart apex can provide thorough washing of the LV cavity. The gradually extending stasis region in the central LV with increasing blood pump support is necessary to reduce the thrombosis potential in the LV.

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