NUMERICAL STUDIES OF THE FLOW STRUCTURE IN THE FINAL DISCHARGE ORIFICE OF EFFERVESCENT ATOMIZER

2012 ◽  
Vol 22 (3) ◽  
pp. 259-274 ◽  
Author(s):  
Baoren Li ◽  
Lingyong Pan ◽  
Gang Yang
Keyword(s):  
Flow Structure ◽  
Numerical Studies ◽  
Effervescent Atomizer ◽  
Discharge Orifice

Effect of the Broken Rib Locations on the Heat Transfer and Fluid Flow in a Rotating Latticework Duct

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Wei Du ◽  
Lei Luo ◽  
Songtao Wang ◽  
Jian Liu ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Nusselt Number ◽  
Wall Shear Stress ◽  
Flow Structure ◽  
Suction Side ◽  
Spiral Flow ◽  
Numerical Studies ◽  
Rotational Number ◽  
Wall Shear

AbstractA numerical method was used to study the effect of the broken rib locations on the heat transfer and flow structure in the latticework duct with various rotational numbers. The latticework duct had eleven subchannels on both the pressure side and the suction side. The crossing angle for each subchannel was 45 deg. The numerical studies were conducted with five different broken rib locations and six rotational numbers (0–0.5). The Reynolds number was fixed as 44,000. The flow structure, wall shear stress, and Nusselt number distributions were analyzed. It was found that the upward spiral flow and helical flow dominated the flow structure in the latticework duct. In addition, the impingement region (at the beginning of the subchannel) induced by the upward spiral flow was responsible for the high Nusselt number and wall shear stress. After adoption of the broken rib in the latticework duct, the Nusselt number was increased by 6.12% on the pressure endwall surface and increased by 6.02% on the rib surface compared to the traditional latticework duct. As the rotational number was increased, the Nusselt number on the pressure endwall surface was decreased by up to 5.4%. However, the high rotational number enhanced the heat transfer on the suction side. The high rotational number also decreased the friction factor in the latticework duct. Furthermore, the overall thermal performance was increased by 12.12% after adoption of the broken ribs on both the turn region and the impingement region.

Numerical studies of the flow structure and aerodynamic forces on two tandem square cylinders with different chamfered-corner ratios

2019 ◽  
Vol 31 (7) ◽  
pp. 075102 ◽  
Author(s):  
Jingmiao Shang ◽  
Qiang Zhou ◽  
Md. Mahbub Alam ◽  
Haili Liao ◽  
Shuyang Cao
Keyword(s):  
Flow Structure ◽  
Aerodynamic Forces ◽  
Numerical Studies ◽  
Square Cylinders ◽  
Tandem Square Cylinders

EFFECT OF GEOMETRICAL PARAMETERS INTERACTION ON SWIRL EFFERVESCENT ATOMIZER SPRAY ANGLE

2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Zulkifli Abdul Ghaffar ◽  
Salmiah Kasolang ◽  
Ahmad Hussein Abdul Hamid ◽  
Ow Chee Sheng ◽  
Mimi Azlina Abu Bakar
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Spray Angle ◽  
Orifice Diameter ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
High Speed Video Camera ◽  
Effervescent Atomizer ◽  
Vane Angle ◽  
Discharge Orifice

A wider spray angle produced by an atomizer is often required in providing a better spray dispersion. The formation and wideness of the spray angle were reported to be affected by the changes in geometrical parameters. In the present study, the effect of the interaction between two geometrical parameters (swirl-generating vane angle and discharge orifice diameter) on the swirl effervescent atomizer spray angle was studied. A newly-designed swirl effervescent atomizer was developed with 30°, 45° and 60° swirl-generating vane angle and 1.5, 2.0 and 2.5mm discharge orifice diameter. The atomizer performance tests were carried out using water as the working fluid and nitrogen gas as the atomizing agent. High-speed shadowgraph technique was deployed to record the resultant sprays produced. Video recordings, acquired using a high-speed video camera, were converted to a sequence of images for further analysis using image processing software. It was found that geometrical parameters of the newly designed atomizer have a great impact on the formation and characteristics of the spray angle. The combined effect of both swirl-generating vane angle and discharge orifice diameter has produced an increase in the spray angle. The largest spray angle was observed at the largest dimension of both geometries.

The influence of imperfections on the flow structure of steady vortex breakdown bubbles

2007 ◽  
Vol 578 ◽  
pp. 453-466 ◽  
Author(s):  
MORTEN BRØNS ◽  
WEN ZHONG SHEN ◽  
JENS NØRKÆR SØRENSEN ◽  
WEI JUN ZHU
Keyword(s):  
Flow Structure ◽  
Vortex Breakdown ◽  
Three Dimensional ◽  
Flow Structures ◽  
Experimental Uncertainty ◽  
Apparent Paradox ◽  
Numerical Studies ◽  
Highly Sensitive ◽  
Bubble Structure ◽  
Three Dimensional Simulations

Vortex breakdown bubbles in the flow in a closed cylinder with a rotating end-cover have previously been successfully simulated by axisymmetric codes in the steady range. However, high-resolution experiments indicate a complicated open bubble structure incompatible with axisymmetry. Numerical studies with generic imperfections in the flow have revealed that the axisymmetric bubble is highly sensitive to imperfections, and that this may resolve the apparent paradox. However, little is known about the influence of specific, physical perturbations on the flow structure. We perform fully three-dimensional simulations of the flow with two independent perturbations: an inclination of the fixed cover and a displacement of the rotating cover. We show that perturbations below a realistic experimental uncertainty may give rise to flow structures resembling those obtained in experiments, that the two perturbations may interact and annihilate their effects, and that the fractal dimension associated with the emptying of the bubble can quantitatively be linked to the visual bubble structure.

scholarly journals Capturing the flow beneath water waves

2017 ◽  
Vol 376 (2111) ◽  
pp. 20170098 ◽  
Author(s):  
A. Nachbin ◽  
R. Ribeiro-Junior
Keyword(s):  
Flow Structure ◽  
Water Waves ◽  
Bottom Topography ◽  
Theme Issue ◽  
Nonlinear Water Waves ◽  
Stagnation Points ◽  
Link Type ◽  
Numerical Studies ◽  
Closed Orbits ◽  
Rotational Waves

Recently, the authors presented two numerical studies for capturing the flow structure beneath water waves (Nachbin and Ribeiro-Junior 2014 Disc. Cont. Dyn. Syst. A 34 , 3135–3153 ( doi:10.3934/dcds.2014.34.3135 ); Ribeiro-Junior et al. 2017 J. Fluid Mech. 812 , 792–814 ( doi:10.1017/jfm.2016.820 )). Closed orbits for irrotational waves with an opposing current and stagnation points for rotational waves were some of the issues addressed. This paper summarizes the numerical strategies adopted for capturing the flow beneath irrotational and rotational water waves. It also presents new preliminary results for particle trajectories, due to irrotational waves, in the presence of a bottom topography. This article is part of the theme issue ‘Nonlinear water waves’.

Numerical Studies on the Performance of Scramjet Combustor with Alternating Wedge-Shaped Strut Injector

2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Gautam Choubey ◽  
K. M. Pandey
Keyword(s):  
Numerical Analysis ◽  
Flow Structure ◽  
Fuel Injection ◽  
Angle Of Attack ◽  
Supersonic Combustion ◽  
Scramjet Combustor ◽  
Numerical Studies ◽  
Scramjet Engine

AbstractNumerical analysis of the supersonic combustion and flow structure through a scramjet engine at Mach 7 with alternating wedge fuel injection and with three angle of attack (

scholarly journals Investigation of the swirled flow structure in the improved four-vortex furnace model

2021 ◽  
Vol 2119 (1) ◽  
pp. 012038
Author(s):  
E Yu Shadrin ◽  
I S Anufriev ◽  
S V Alekseenko
Keyword(s):  
Flow Structure ◽  
Vortex Flow ◽  
Laser Doppler Anemometry ◽  
Three Dimensional ◽  
Vortex Furnace ◽  
The Core ◽  
Numerical Studies ◽  
The Mathematical Model ◽  
Swirled Flow ◽  
Good Agreement

Abstract The flow structure in a model of promising four-vortex furnace is investigated using three-dimensional laser Doppler anemometry method (3D-LDA). Using the “minimum total pressure” criterion, a vortex flow structure was visualized: the core looks like a deformed elliptical cylinder. Results has been compared with early PIV experiments and showed good agreement. The mathematical model for full-scale furnace numerical studies can be verified using these data.

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