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.

Performance calculation of electrothermal anti-icing system on three-dimensional surface

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040106
Author(s):  
Zheng-Zhi Wang ◽  
Chong-Yang Liu ◽  
Chun-Ling Zhu ◽  
Ning Zhao
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer Coefficient ◽  
Three Dimensional ◽  
Leading Edge ◽  
Mass Transfer Process ◽  
Protection Systems ◽  
The Mathematical Model ◽  
Performance Calculation ◽  
Dimensional Surface ◽  
Good Agreement

The electrothermal anti-icing system is one of the commonly used ice protection systems. In this paper, the heat and mass transfer process on three-dimensional surface of the electrothermal anti-icing system is analyzed. The mass and energy conservation equations are given. A calculation method of the convective heat transfer coefficient on three-dimensional surface is proposed, and the mathematical model of the electrothermal anti-icing system is established. The model is applied to calculate the temperature distribution of the anti-icing system in different conditions. The numerical results are compared with experimental data, and the good agreement between them proves that the developed method is reliable. The results also show that only part of droplets impacted on the leading edge evaporate immediately, while the rest of droplets move downstream in the form of liquid water and evaporate gradually.

3-D Simulation of Conservative and Non-Conservative Density Current

2006 ◽  
Author(s):  
S. Hormozi ◽  
B. Firoozabadi ◽  
H. Ghasvari Jahromi ◽  
S. M. H. Moosavi Hekmati
Keyword(s):  
Flow Structure ◽  
Environmental Flows ◽  
Three Dimensional ◽  
Turbidity Currents ◽  
Density Current ◽  
Density Currents ◽  
Straight Channel ◽  
Suspended Material ◽  
Series Of Experiments ◽  
Good Agreement

Flows generated by density differences are called gravity or density currents which are generic features of many environmental flows. These currents are classified as the conservative and non-conservative flows whether the buoyancy flux is conserved or changed respectively. In this paper, a low Reynolds k-ε turbulence model is used to simulate three dimensional density and turbidity currents. Also, a series of experiments were conducted in a straight channel to study the characteristics of the non-conservative density current. In experiments, Kaolin was used as the suspended material. Comparisons are made between conservative and non-conservative's height, concentration and velocity profiles of the current and their variations along the transverse intersections. Outcomes indicate that the presence of the particles influences the flow structure sensibly. The results are compared with the experiments and showed a good agreement.

Computation of Three-Dimensional Turbulent Flows in a Pipe Junction with Reference to Engine Inlet Manifolds

1992 ◽  
Vol 206 (4) ◽  
pp. 285-296 ◽  
Author(s):  
H Fu ◽  
M J Tindal ◽  
A P Watkins ◽  
M Yianneskis
Keyword(s):  
Turbulent Flows ◽  
Combustion Engine ◽  
Laser Doppler Anemometry ◽  
Numerical Study ◽  
Three Dimensional ◽  
Turbulence Energy ◽  
Numerical Predictions ◽  
Split Ratio ◽  
Inlet Manifold ◽  
Good Agreement

This paper presents a numerical study of the flows in an internal combustion engine inlet manifold. The three-dimensional turbulent flows through a single branched manifold were simulated using the κ-ɛ model of turbulence. The flow structure was characterized in detail and the effects of the flow split ratio and inlet flowrate were investigated. Detailed measurements were performed to validate the numerical predictions, using laser Doppler anemometry. Good agreement was obtained between the predicted and the measured mean velocities. The predicted levels of turbulence energy are in qualitative agreement with the measurements.

Three-dimensional flow in circular cavities of large spanwise aspect ratio

2012 ◽  
Vol 707 ◽  
pp. 551-574 ◽  
Author(s):  
Owen Tutty ◽  
Ralph Savelsberg ◽  
Ian P. Castro
Keyword(s):  
Vortex Flow ◽  
Radial Profile ◽  
Three Dimensional ◽  
Circular Cavity ◽  
Two Dimensional ◽  
Viscous Effects ◽  
Three Dimensional Flow ◽  
Core Flow ◽  
The Core ◽  
Separated Shear Layer

AbstractExperimental data are presented for the vortex flow in a nominally two-dimensional circular cavity. The vortex is driven by a separated shear layer along an open section of the cavity circumference. It is shown that the core vortex flow is perturbed three-dimensionally. An inviscid analysis of an ideal core (solid body) vortex is given and it is shown that this flow contains a steady perturbation whose characteristics are almost exactly those identified in the experiments. Viscous effects reduce (by a few per cent) the spanwise wavelength of the perturbation and also lead, via spatial variations in Reynolds stress, to a modification of the core flow so that the radial profile of the circumferential velocity is ‘S’-shaped, rather than linear.

scholarly journals Design, Plant Test and CFD Calculation of a Turbocharger for a Low-Speed Engine

2020 ◽  
Vol 10 (23) ◽  
pp. 8344
Author(s):  
Aleksey Borovkov ◽  
Igor Voinov ◽  
Yuri Galerkin ◽  
Roman Kaminsky ◽  
Aleksandr Drozdov ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Three Dimensional ◽  
Significant Discrepancy ◽  
One Dimensional ◽  
Peter The Great ◽  
Plant Test ◽  
Computational Fluid Dynamics Cfd ◽  
The Mathematical Model ◽  
Speed Engine ◽  
Good Agreement

Various approaches and techniques are used to design centrifugal compressors. These are engineering one-dimensional and quasi-three-dimensional programs, as well as CFD Computational Fluid Dynamics (CFD) programs. The final judgment about the effectiveness of the design is given by testing the compressor or its model. A centrifugal compressor for an internal combustion engine turbocharger was designed jointly by the Research Laboratory “Gas Dynamics of Turbomachines” of Peter the Great St. Petersburg Polytechnic University (SPbPU) and RPA (Research and Production Association) “Turbotekhnika”. To check its dimensionless characteristics, the compressor was tested with two geometrically similar impellers with a diameter of 175 (TKR 175E) and 140 mm (TKR 140E). The mathematical model of the Universal Modeling Method calculates the efficiency in the design mode for all tests of both compressors with an error of 0.89%, and the efficiency for the entire characteristic with an error of 1.55%. The characteristics of the TKR 140E compressor were calculated using the ANSYS commercial CFD software. For TKR-140E, a significant discrepancy in the value of the efficiency was obtained, but a good agreement in the area of operation, which was not achieved in previous calculations. According to the calculation, the work coefficient is overestimated by 9%, which corresponds to the results of previous calculations by the authors.

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.

The finite-length square cylinder near wake

2009 ◽  
Vol 638 ◽  
pp. 453-490 ◽  
Author(s):  
H. F. WANG ◽  
Y. ZHOU
Keyword(s):  
Flow Visualization ◽  
Flow Structure ◽  
Finite Length ◽  
Laser Doppler Anemometry ◽  
Three Dimensional ◽  
Width Ratio ◽  
Stream Velocity ◽  
Cylinder Wake ◽  
Square Cylinder ◽  
Near Wake

This paper reports an experimental investigation of the near wake of a finite-length square cylinder, with one end mounted on a flat plate and the other free. The cylinder aspect ratio or height-to-width ratio H/d ranges from 3 to 7. Measurements were carried out mainly in a closed-loop low-speed wind tunnel at a Reynolds number Red, based on d and the free-stream velocity of 9300 using hot-wire anemometry, laser Doppler anemometry and particle image velocimetry (PIV). The planar PIV measurements were performed in the three orthogonal planes of the three-dimensional cylinder wake, along with flow visualization conducted simultaneously in two orthogonal planes (Red = 221). Three types of vortices, i.e. the tip, base and spanwise vortices were observed and the near wake is characterized by the interactions of these vortices. Both flow visualization and two-point correlation point to an inherent connection between the three types of vortices. A model is proposed for the three-dimensional flow structure based on the present measurements, which is distinct from previously proposed models. The instantaneous flow structure around the cylinder is arch-type, regardless of H/d, consisting of two spanwise vortical ‘legs’, one on each side of the cylinder, and their connection or ‘bridge’ near the free end. Both tip and base vortices are the streamwise projections of the arch-type structure in the (y, z) plane, associated with the free-end downwash flow and upwash flow from the wall, respectively. Other issues such as the topological characteristics, spatial arrangement and interactions among the vortical structures are also addressed.

The Mean Flow Structure Around and Within a Turbulent Junction or Horseshoe Vortex—Part I: The Upstream and Surrounding Three-Dimensional Boundary Layer

1988 ◽  
Vol 110 (4) ◽  
pp. 406-414 ◽  
Author(s):  
J. D. Menna ◽  
F. J. Pierce
Keyword(s):  
Boundary Layer ◽  
Flow Structure ◽  
Vortex Flow ◽  
Three Dimensional ◽  
Horseshoe Vortex ◽  
Mean Flow ◽  
Complex Flow ◽  
Mean Velocity ◽  
Standard Case ◽  
The Mean

The mean flow structure upstream, around, and in a turbulent junction or horseshoe vortex is reported for an incompressible, subsonic flow. This fully documented, unified, comprehensive, and self-consistent data base is offered as a benchmark or standard case for assessing the predictive capabilities of computational codes developed to predict this kind of complex flow. Part I of these papers defines the total flow being documented. The upstream and surrounding three-dimensional turbulent boundary layer-like flow away from separation has been documented with mean velocity field and turbulent kinetic energy field measurements made with hot film anemometry, and local wall shear stress measurements. Data are provided for an initial condition plane well upstream of the junction vortex flow to initiate a boundary layer calculation, and freestream or edge velocity, as well as floor static pressure, are reported to proceed with the solution. Part II of these papers covers the flow through separation and within the junction vortex flow.

CAD Software Development for the Continuous Flexible Forming Process

2011 ◽  
Vol 189-193 ◽  
pp. 2907-2910
Author(s):  
Lin Liu ◽  
Zhong Yi Cai ◽  
Shao Hui Wang ◽  
Mine Zhe Li
Keyword(s):  
Three Dimensional ◽  
Cad Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Flexible Forming ◽  
The Core ◽  
Core Function ◽  
Flexible Forming Process ◽  
The Mathematical Model

The software for the continuous flexible forming process was developed using Visual C++ platform. It can directly read the triangular mesh data of the CAD model. The three-dimensional model was reconstructed rapidly by using the core function of the OpenGL. Moreover, the mathematical model of adjusting the flexible rolls and the longitudinal curvature were established by this software. Using these mathematical descriptions the simulation of the continuous flexible forming process can be finished from the viewpoint of geometry.

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