Swirl Turbocharging Exhaust System and its Application Study

2001 ◽  
Author(s):  
Huimeng Liu ◽  
Yongchang Liu ◽  
Li Cao
Keyword(s):  
Flow Field ◽  
Flow Behavior ◽  
Exhaust System ◽  
Exhaust Manifold ◽  
Test Results ◽  
Application Study ◽  
Turbocharging System ◽  
Calculation Results ◽  
Flow Field Characteristics ◽  
New Type

Abstract A novel modular single exhaust manifold called swirl turbocharging exhaust system is described. The flow field was modeled and compared with the flow behavior in MPC system. Numerical calculation results of the manifold flow show that its flow field characteristics were different from that of the MPC’s. To investigate the efficient two swirl turbocharging exhaust systems were designed and applied to two turbocharged diesel engines respectively. The test results reveal that both engines with the new type turbocharging system have promising performance.

scholarly journals SPH Simulation of Interior and Exterior Flow Field Characteristics of Porous Media

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 918 ◽  
Author(s):  
Shijie Wu ◽  
Matteo Rubinato ◽  
Qinqin Gui
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Flow Field ◽  
Boundary Conditions ◽  
Water Waves ◽  
Flow Behavior ◽  
Simulation Method ◽  
Interface Problem ◽  
Ocean Engineering ◽  
Flow Field Characteristics

At the present time, one of the most relevant challenges in marine and ocean engineering and practice is the development of a mathematical modeling that can accurately replicate the interaction of water waves with porous coastal structures. Over the last 60 years, multiple techniques and solutions have been identified, from linearized solutions based on wave theories and constant friction coefficients to very sophisticated Eulerian or Lagrangian solvers of the Navier-Stokes (NS) equations. In order to explore the flow field interior and exterior of the porous media under different working conditions, the Smooth Particle Hydrodynamics (SPH) numerical simulation method was used to simulate the flow distribution inside and outside a porous media applied to interact with the wave propagation. The flow behavior is described avoiding Euler’s description of the interface problem between the Euler mesh and the material selected. Considering the velocity boundary conditions and the cyclical circulation boundary conditions at the junction of the porous media and the water flow, the SPH numerical simulation is used to analyze the flow field characteristics, as well as the longitudinal and vertical velocity distribution of the back vortex flow field and the law of eddy current motion. This study provides innovative insights on the mathematical modelling of the interaction between porous structures and flow propagation. Furthermore, there is a good agreement (within 10%) between the numerical results and the experimental ones collected for scenarios with porosity of 0.349 and 0.475, demonstrating that SPH can simulate the flow patterns of the porous media, the flow through the inner and outer areas of the porous media, and the flow field of the back vortex region. Results obtained and the new mathematical approach used can help to effectively simulate with high-precision the changes along the water depth, for a better design of marine and ocean engineering solutions adopted to protect coastal areas.

scholarly journals Elastic Turbulence of Aqueous Polymer Solution in Multi-Stream Micro-Channel Flow

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 110 ◽  
Author(s):  
Jiayan Tai ◽  
Yee Cheong Lam
Keyword(s):  
Flow Field ◽  
Channel Flow ◽  
Flow Instability ◽  
Flow Behavior ◽  
Power Spectra ◽  
Micro Channel ◽  
Polymer Molecules ◽  
Aqueous Solvent ◽  
Micro Channels ◽  
Flow Field Characteristics

Viscous liquid flow in micro-channels is typically laminar because of the low Reynolds number constraint. However, by introducing elasticity into the fluids, the flow behavior could change drastically to become turbulent; this elasticity can be realized by dissolving small quantities of polymer molecules into an aqueous solvent. Our recent investigation has directly visualized the extension and relaxation of these polymer molecules in an aqueous solution. This elastic-driven phenomenon is known as ‘elastic turbulence’. Hitherto, existing studies on elastic flow instability are mostly limited to single-stream flows, and a comprehensive statistical analysis of a multi-stream elastic turbulent micro-channel flow is needed to provide additional physical understanding. Here, we investigate the flow field characteristics of elastic turbulence in a 3-stream contraction-expansion micro-channel flow. By applying statistical analyses and flow visualization tools, we show that the flow field bares many similarities to that of inertia-driven turbulence. More interestingly, we observed regions with two different types of power-law dependence in the velocity power spectra at high frequencies. This is a typical characteristic of two-dimensional turbulence and has hitherto not been reported for elastic turbulent micro-channel flows.

PIV Measurements of Recirculation Patterns in a Stirred Tank

2001 ◽  
Author(s):  
Khaled J. Hammad ◽  
George Papadopoulos
Keyword(s):  
Flow Field ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Vertical Plane ◽  
Vertical Axis ◽  
Transitional Flow ◽  
Piv Measurements ◽  
Vortical Structures ◽  
Blade Passage ◽  
Flow Field Characteristics

Abstract Phase-resolved PIV measurements were performed to reveal the detailed flow features within a triple impeller stirredtank. Two tests were performed: low and high rotational speeds, 175 and 575 RPM, respectively. The tests used an optically transparent mixing vessel to measure the 2D flow field characteristics along a vertical plane passing through the tank center. The measurements disclosed interesting in-plane vortical behavior that when measured at two angular positions with respect to the blade passage further indicated the three-dimensional flow behavior. For the low RPM case, a laminar flow nature was apparent, whereby vortical toroidal structures spanned around the stirrer vertical axis. Six such structures were dominant. For the high RPM case and for θ = 0° six dominant vortical structures were apparent. Their r-z plane location and size were different from that for the low RPM case. With blade passage four of these vortical structures appeared to merge into two, suggesting that constant toroidal vortical structures spanning around the stirrer axis were absent from the high RPM case. A switch between six distinct and four distinct in-plane vortical structures as the blades pass through the measurement plane further suggested a transitional flow field at 575 RPM.

Test and FEM Analysis on a New Type of Anti-Wind Device

2012 ◽  
Vol 268-270 ◽  
pp. 697-701
Author(s):  
Chao Yong Shen ◽  
Yu Hong Ma ◽  
Min Hui Zhou
Keyword(s):  
Ultimate Strength ◽  
Seismic Design ◽  
Fem Analysis ◽  
Scale Model ◽  
Design Calculation ◽  
Test Results ◽  
Calculation Results ◽  
New Type ◽  
Intermediate Section

A new type of anti-wind device was put forward. 1/4 scale model about it had been tested and analyzed by FEM. Comparison of FEM, design calculation results with test results also had been done.Test and FEM results show the intermediate section will be the most weakness part, no matter that it is on the condition of in-plane load or out-plane load. During the stage of anti-wind design, it is safe for the FEM, design calculation results in which the standard strength of material is used, but at the stage of seismic design, the ultimate strength of anti-wind device should be considered in order to assure the anti-wind device to damage while earthquake happens.

Influence of Guide Vanes' Angle on Flow Fields of Cylinder Cage Powder Classifier

2012 ◽  
Vol 263-266 ◽  
pp. 843-846 ◽  
Author(s):  
Da Zhi Jiang ◽  
Jing Han
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Flow Behavior ◽  
Air Flow ◽  
Flow Fields ◽  
Guide Vanes ◽  
Flow Field Characteristics ◽  
Computational Fluid Dynamics Cfd ◽  
The Stability

To research guide vanes' influences on flow fields of cylinder cage powder classifier at different angles, a study of guide vanes under 3 different angles is therefore undertaken examining air flow behavior. The investigation of these flow field characteristics made use of the computational fluid dynamics (CFD) to simulate the air flow in the classifier. The results indicate that smaller angles of guide vanes can increase velocity but damage the stability of flow fields, and that those larger angles will reduce the velocity.

Prediction of the Thermal Injury Around Exhaust System of Passenger Car by Practical Procedure: 1st Report—Development of 1D Model for Heat Analysis

2011 ◽  
Author(s):  
Ituhei Kohri ◽  
Eriko Hara ◽  
Tohru Komoriya ◽  
Shuji Miyamoto
Keyword(s):  
Flow Field ◽  
Industrial Development ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Vehicle Body ◽  
Engine Compartment ◽  
Heat Injury ◽  
Practical Procedure ◽  
Calculation Results ◽  
Exhaust Systems

In case that heat injury performance is analyzed with CFD, large calculations are required to solve heat and mass flow field inside the exhaust pipes, in the engine compartment and around vehicle body simultaneously. Since it spends much time for the generation of the analytic models and their solution by full CFD, such calculations are not practical to the industrial development of the vehicle in which many parameter studies on various conditions are required. Wherein, we suggest new method for prediction of the heat injury on exhaust systems, which is simplified with 1 dimensional models though the engine compartment flow is calculated with 3 dimensional calculations, i.e. CFD. Basic idea of this method is to divide exhaust systems into several elemental modules where heat transfer characteristics are given individually and to imitate actual systems by connecting them. Then 3D calculation is processed coupling heat and flow field with radiant filed outside exhaust systems. Above all, chemical reaction occurs in the catalytic converter is solved carefully to estimate heat production. This report introduces an overview of their 1-dimensional model and the calculation results.

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