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.

Mechanism and Flow Control on the Mismatching of Impeller and Vaned Diffuser Caused by Inlet Prewhirl for Centrifugal Compressors

2016 ◽  
Author(s):  
Qiangqiang Huang ◽  
Xinqian Zheng ◽  
Aolin Wang
Keyword(s):  
Flow Control ◽  
Control Method ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Vaned Diffuser ◽  
Inlet Distortion ◽  
Computational Fluid Dynamics Cfd ◽  
Stagger Angle ◽  
Good Agreement ◽  
Matching Relation

Air often flows into compressors with inlet prewhirl, because it will obtain a circumferential component of velocity via inlet distortion or swirl generators such as inlet guide vanes. A lot of research has shown that inlet prewhirl does influence the characteristics of components, but the change of the matching relation between the components caused by inlet prewhirl is still unclear. This paper investigates the influence of inlet prewhirl on the matching of the impeller and the diffuser and proposes a flow control method to cure mismatching. The approach combines steady three-dimensional Reynolds-averaged Navier-Stokes (RANS) simulations with theoretical analysis and modeling. The result shows that a compressor whose impeller and diffuser match well at zero prewhirl will go to mismatching at non-zero prewhirl. The diffuser throat gets too large to match the impeller at positive prewhirl and gets too small for matching at negative prewhirl. The choking mass flow of the impeller is more sensitive to inlet prewhirl than that of the diffuser, which is the main reason for the mismatching. To cure the mismatching via adjusting the diffuser vanes stagger angle, a one-dimensional method based on incidence matching has been proposed to yield a control schedule for adjusting the diffuser. The optimal stagger angle predicted by analytical method has good agreement with that predicted by computational fluid dynamics (CFD). The compressor is able to operate efficiently in a much broader flow range with the control schedule. The flow range, where the efficiency is above 80%, of the datum compressor and the compressor only employing inlet prewhirl and no control are just 25.3% and 31.8%, respectively. For the compressor following the control schedule, the flow range is improved up to 46.5%. This paper also provides the perspective of components matching to think about inlet distortion.

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.

scholarly journals Strong and Reversible Adhesion of Interlocked 3D-Microarchitectures

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 48 ◽  
Author(s):  
Minho Seong ◽  
Hyun-Ha Park ◽  
Insol Hwang ◽  
Hoon Eui Jeong
Keyword(s):  
Aspect Ratio ◽  
Structural Stability ◽  
High Aspect Ratio ◽  
Three Dimensional ◽  
Normal Direction ◽  
One Dimensional ◽  
Reversible Adhesion ◽  
Adhesion Behavior ◽  
Organic Nanomaterials ◽  
Good Agreement

Diverse physical interlocking devices have recently been developed based on one-dimensional (1D), high-aspect-ratio inorganic and organic nanomaterials. Although these 1D nanomaterial-based interlocking devices can provide reliable and repeatable shear adhesion, their adhesion in the normal direction is typically very weak. In addition, the high-aspect-ratio, slender structures are mechanically less durable. In this study, we demonstrate a highly flexible and robust interlocking system that exhibits strong and reversible adhesion based on physical interlocking between three-dimensional (3D) microscale architectures. The 3D microstructures have protruding tips on their cylindrical stems, which enable tight mechanical binding between the microstructures. Based on the unique 3D architectures, the interlocking adhesives exhibit remarkable adhesion strengths in both the normal and shear directions. In addition, their adhesion is highly reversible due to the robust mechanical and structural stability of the microstructures. An analytical model is proposed to explain the measured adhesion behavior, which is in good agreement with the experimental results.

scholarly journals ICCM2015: A Comparison of RANS and LES Computational Methods in Analyzing Ventilation Flow Through a Room Fitted with a Two-Sided Windcatcher

2017 ◽  
Vol 14 (03) ◽  
pp. 1750021 ◽  
Author(s):  
A. Niktash ◽  
B. P. Huynh
Keyword(s):  
Natural Ventilation ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Interior Space ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Cfd Method ◽  
Good Agreement

A windcatcher is a structure for providing natural ventilation using wind power; it is usually fitted on the roof of a building to exhaust the inside stale air to the outside and supplies the outside fresh air into the building interior space working by pressure difference between outside and inside of the building. In this paper, the behavior of free wind flow through a three-dimensional room fitted with a centered position two-canal bottom shape windcatcher model is investigated numerically, using a commercial computational fluid dynamics (CFD) software package and LES (Large Eddy Simulation) CFD method. The results have been compared with the obtained results for the same model but using RANS (Reynolds Averaged Navier–Stokes) CFD method. The model with its surrounded space has been considered in both method. It is found that the achieved results for the model from LES method are in good agreement with RANS method’s results for the same model.

Design of a Compact Crossover Diffuser for Micro Gas Turbines Using a Mean-Line Code

2019 ◽  
Vol 36 (4) ◽  
pp. 347-357
Author(s):  
C.J. Burger ◽  
S.J. van der Spuy ◽  
T.W. von Backström
Keyword(s):  
Gas Turbines ◽  
Optimized Design ◽  
One Dimensional ◽  
Micro Gas Turbine ◽  
Engine Thrust ◽  
Design Variables ◽  
Performance Effects ◽  
Computational Fluid Dynamics Cfd ◽  
And Performance ◽  
Good Agreement

Abstract The design and validation of a Compact Crossover Diffuser (CCD) to replace the size-limited radial diffuser and axial de-swirl cascade of an existing Micro Gas Turbine (MGT) is discussed. A CCD strives to combine the performance of a channel diffuser with the operating range and efficiency of a vaneless diffuser. The development of a one-dimensional Mean-Line Code (MLC) is presented, which aids the designer in preliminary design and performance evaluation of the CCD. Design graphs indicating the performance effects of changing the primary design variables are developed and shown. The MLC is numerically validated using Computational Fluid Dynamics (CFD). Good agreement is seen between the MLC and CFD results, predicting the design point PRss(2-4) to within 1.4 %. A CFD optimized CCD was manufactured and tested. Agreement between the CFD and experimental results for PRts(0-4) is within 7.58 % at 106 kRPM. A numerically predicted increase in PRts(0-4) from 3.31, to 3.53, to 3.83 is seen for the vaneless-, MLC optimized-, and CFD optimized-design respectively. An experimental increase of 82.3 % in engine thrust and 80.0 % in total-to-static pressure recovery across the compressor stage was measured when retrofitting the BMT120KS with a new impeller and CCD.

scholarly journals Simulation Study of LPG Cooking Burner

2018 ◽  
Vol 7 (3.7) ◽  
pp. 142 ◽  
Author(s):  
Mana Wichangarm ◽  
Anirut Matthujak ◽  
Thanarath Sriveerakul ◽  
Sedthawatt Sucharitpwatskul ◽  
Sutthisak Phongthanapanich
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Flame Structure ◽  
Three Dimensional ◽  
Cfd Model ◽  
Flow Feature ◽  
Combustion Region ◽  
Computational Fluid Dynamics Cfd ◽  
The Heat Transfer Coefficient ◽  
Good Agreement

The objective of this paper is to numerically study the flow feature and combustion phenomena of an energy-saving cooking burner using three-dimensional computational fluid dynamics (CFD). Combustion temperatures were experimentally and numerically investigated in order to not only validate the CFD model, but also describe the combustion phenomena. From the temperature comparison, the CFD model was good agreement with the experiment, having the error of less than 5.86%. Based upon the insight from the CFD model, the high temperature of 1,286 K occurred at the middle of the burner. The high intensive vortex of the flow being enhanced the combustion intensity and the heat transfer coefficient is obvious observed near the burner head inside the ring. Therefore, it is concluded that the burner ring is the major part since it controls flame structure, high temperature region, intensive combustion region, heat loss and suitable flow feature. However, heat transfer to the vessel should be further clarified by the CFD model.   

The new one-dimensional coordination polymercatena-poly[[diaquasodium(I)]-μ-oxalato-[diaquairon(III)]-μ-oxalato]

2016 ◽  
Vol 72 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Mohamed Al Amine Benhacine ◽  
Malika Hamadène ◽  
Sofiane Bouacida ◽  
Hocine Merazig
Keyword(s):  
Three Dimensional ◽  
Local Symmetry ◽  
Ternary Oxide ◽  
Inorganic Polymers ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
One Dimensional ◽  
Oxalate Ligand ◽  
Metal Oxalate ◽  
Good Agreement

The oxalate dianion is one of the most studied ligands and is capable of bridging two or more metal centres and creating inorganic polymers based on the assembly of metal polyhedra with a wide variety of one-, two- or three-dimensional extended structures. Yellow single crystals of a new mixed-metal oxalate, namelycatena-poly[[diaquasodium(I)]-μ-oxalato-κ4O1,O2:O1′,O2′-[diaquairon(III)]-μ-oxalato-κ4O1,O2:O1′,O2′], [NaFe(C2O4)2(H2O)4]n, have been synthesized and the crystal structure elucidated by X-ray diffraction analysis. The compound crystallizes in the noncentrosymmetric space groupI41(Z= 4). The asymmetric unit contains one NaIand one FeIIIatom lying on a fourfold symmetry axis, one μ2-bridging oxalate ligand and two aqua ligands. Each metal atom is surrounded by two chelating oxalate ligands and two equivalent water molecules. The structure consists of infinite one-dimensional chains of alternating FeO4(H2OW1)2and NaO4(H2OW2)2octahedra, bridged by oxalate ligands, parallel to the [100] and [010] directions, respectively. Because of thecisconfiguration and the μ2-coordination mode of the oxalate ligands, the chains run in a zigzag manner. This arrangement facilitates the formation of hydrogen bonds between neighbouring chains involving the H2O and oxalate ligands, leading to a two-dimensional framework. The structure of this new one-dimensional coordination polymer is shown to be unique among theAIMIII(C2O4)2(H2O)nseries. In addition, the absorption bands in the IR and UV–Visible regions and their assignments are in good agreement with the local symmetry of the oxalate ligand and the irregular environment of iron(III). The final product of the thermal decomposition of this precursor is the well-known ternary oxide NaFeO2.

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.

Assessment of zero-dimensional, hybrid and multidimensional simulations for transient air flow through a cylinder-duct assembly

2003 ◽  
Vol 217 (5) ◽  
pp. 585-591
Author(s):  
S Bakshi ◽  
R V Ravikrishna
Keyword(s):  
Hybrid Approach ◽  
Three Dimensional ◽  
Dimensional Approach ◽  
Lumped Parameter ◽  
Pressure Time ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Parameter Approach ◽  
Experimental Pressure ◽  
Good Agreement

The pressure-time characteristics for the charging process of a cylinder with a piston-controlled port through a connecting duct is studied with the objective of assessing the accuracy of various methods such as the lumped parameter or zero-dimensional approach, an intermediate hybrid approach and a full three-dimensional computational fluid dynamics (CFD) calculation. The predictions from all the approaches are compared with experimental data. It is observed that, for a particular cup-shaped geometry of the piston, both the zero-dimensional and hybrid approach overpredict the pressure recovery rate in comparison with the three-dimensional CFD calculation, which is in good agreement with the experimental pressure-time variation. On the other hand, the agreement between the lumped parameter approach and the detailed CFD calculation is better for a flat piston, indicating the importance of the piston geometry.

scholarly journals A tool for multi-scale modelling of the renal nephron

2011 ◽  
Vol 1 (3) ◽  
pp. 417-425 ◽  
Author(s):  
David P. Nickerson ◽  
Jonna R. Terkildsen ◽  
Kirk L. Hamilton ◽  
Peter J. Hunter
Keyword(s):  
Mathematical Model ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Scale Model ◽  
Model Description ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Multi Scale ◽  
The Mathematical Model

We present the development of a tool, which provides users with the ability to visualize and interact with a comprehensive description of a multi-scale model of the renal nephron. A one-dimensional anatomical model of the nephron has been created and is used for visualization and modelling of tubule transport in various nephron anatomical segments. Mathematical models of nephron segments are embedded in the one-dimensional model. At the cellular level, these segment models use models encoded in CellML to describe cellular and subcellular transport kinetics. A web-based presentation environment has been developed that allows the user to visualize and navigate through the multi-scale nephron model, including simulation results, at the different spatial scales encompassed by the model description. The Zinc extension to Firefox is used to provide an interactive three-dimensional view of the tubule model and the native Firefox rendering of scalable vector graphics is used to present schematic diagrams for cellular and subcellular scale models. The model viewer is embedded in a web page that dynamically presents content based on user input. For example, when viewing the whole nephron model, the user might be presented with information on the various embedded segment models as they select them in the three-dimensional model view. Alternatively, the user chooses to focus the model viewer on a cellular model located in a particular nephron segment in order to view the various membrane transport proteins. Selecting a specific protein may then present the user with a description of the mathematical model governing the behaviour of that protein—including the mathematical model itself and various simulation experiments used to validate the model against the literature.

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