Research of 3D-CFD Simulation on a Large Sized Pit Type Carburizing Furnace

2006 ◽  
Vol 118 ◽  
pp. 337-342
Author(s):  
Wei Min Zhang ◽  
Ye Ma ◽  
Lin Lin Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Cfd Simulations ◽  
3 Dimensional ◽  
Set Up ◽  
Carburizing Process

A fluid dynamic model was set up to describe the flow field of gas in a large sized pit type carburizing furnace when large sized gears were being carburized. The commercial software Fluent was adopted to carry out 3 dimensional computational fluid dynamics (3D-CFD) simulations of the gas flow field under different, actually four kinds of , furnace designs in this article. The flow fields of the carburizing gas around the part were analyzed. According to the simulations and analysis, it was shown that the number of fans on gear’s carburizing is not a primary factor, using a air inducting tub can improve the carburizing process significantly and proper loading tray design can also be positive. The results indicate that the simulation provides a reference to the furnace’s design optimization.

scholarly journals Optimization and Application of D850 Dredge Pump Blades under Medium Coarse Sand Condition of Cutter Suction Dredger

2021 ◽  
Vol 2097 (1) ◽  
pp. 012005
Author(s):  
Haifei Zhuang ◽  
Mingming Liu ◽  
Yongding Wu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Uniform Distribution ◽  
Fuel Consumption ◽  
Cfd Simulation ◽  
Coarse Sand ◽  
Solid Particles ◽  
Data Comparison ◽  
Computational Fluid Dynamics Cfd

Abstract Regarding wear issues of a dredge pump’s impeller as a cutter suction dredger transports medium coarse sand slurry, blades of the D850 dredge pump are modified and optimized, which extends the distance from the blade inlet root to the impeller suction and avoids damages of the impeller suction anti-wear ring. Analyses via computational fluid dynamics (CFD) simulation show that the head and the efficiency after blade modification have little changes compared with before optimization in the construction flow range of 10000-12000 m3/h under coarse sand condition. While it improves the flow field of impeller’s channels, decreases the vortex at the inlet root of the blades, ensures more uniform distribution of the solid particles. Meanwhile, this is beneficial to reductions of the channels’ wears. Applications from constructions show some improvements in the wears of the blade root. Through the construction data comparison, after replacing the modified impeller, dredging productivity will be increased by 15.1% and the fuel consumption per 10000 m3 will be then reduced by 11.5%.

scholarly journals Computational Fluid Dynamics Simulation of Airflow and Air Pattern in the Living Room for Reducing Coronavirus Exposure

2021 ◽  
Author(s):  
Majid Bayatian ◽  
Khosro Ashrafi ◽  
Zahra Amiri ◽  
Elahe Jafari
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Dynamics Simulation ◽  
Living Room ◽  
Air Velocity ◽  
Cfd Validation ◽  
Airflow Pattern

Abstract Viruses can be transmitted in indoor environments. Important factors in Indoor Air Quality (IAQ) are air velocity, relative humidity, temperature, and airflow pattern and Computational fluid dynamics (CFD) can use for IAQ assessment. The objective of this study is to CFD simulation in the living room to the prediction of the air pattern and air velocity. A computational fluid dynamic model was applied for airflow pattern and air velocity simulation. For simulation, GAMBIT, FLUENT, and CFD post software were used as preprocessing, processing, and post-processing, respectively. CFD validation was carried out by comparing the computed data with the experimental measurements. The final mesh number was set to 1,416,884 elementary cells and SIMPLEC algorithm was used for pressure-velocity coupling. PERSTO, and QUIK schemes have been used for the pressure terms, and the other variables, respectively. Simulations were carried out in ACH equals 3, 6 and 8 in four lateral walls. The maximum error and root mean square error from the air velocity were 14% and 0.10, respectively. Terminal settling velocity and relaxation time were equal to 0.302 ×10− 2 m/s and 0.0308 ×10− 2 s for 10 µm diameter particles, respectively. The stopping distance was 0.0089m and 0.011m for breathing and talking, respectively. The maximum of mean air velocity is in scenario 4 with ACH = 8 that mean air velocity is equal to 0.31 in 1.1m height, respectively. The results of this study showed that avoiding family gatherings is necessary for exposure control and suitable airflow and pattern can be improving indoor air conditions.

CFD Simulation on Flow Field of Gas-Liquid Taylor Flow in Circular Capillaries

2013 ◽  
Vol 803 ◽  
pp. 54-59
Author(s):  
Zhi Qun Pan ◽  
Xu Bin Zhang ◽  
Jing Tang ◽  
Wang Feng Cai
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Cfd Simulation ◽  
Unit Length ◽  
Bubble Velocity ◽  
Gas Bubble ◽  
Liquid Slug ◽  
Taylor Flow ◽  
Computational Fluid Dynamics Cfd

Computational Fluid Dynamics (CFD) was used to simulate the flow field of gas-liquid Taylor flow in circular capillaries. The separate influence of gas bubble velocityVb,Taylor unit lengthLUC, film lengthLfilmand liquid film thicknessδfilmon both the liquid slug velocityVx,topand film velocityVx,filmwere investigated. The values ofVx,topare mainly dependent onVbandδfilmwhileVx,filmrelies on all the four parameters.

scholarly journals Aerodynamics Analysis of Speed Skating Helmets: Investigation by CFD Simulations

2021 ◽  
Vol 11 (7) ◽  
pp. 3148
Author(s):  
Guillermo Puelles Magán ◽  
Wouter Terra ◽  
Andrea Sciacchitano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Numerical Simulations ◽  
Turbulence Model ◽  
Aerodynamic Drag ◽  
Cfd Simulations ◽  
Speed Skating ◽  
Computational Fluid Dynamics Cfd ◽  
Rans Simulations

In this work, we investigate the flow field around speed skating helmets and their associated aerodynamic drag by means of computational fluid dynamics (CFD) simulations. An existing helmet frequently used in competition was taken as a baseline. Six additional helmet designs, as well as the bare-head configuration, were analysed. All the numerical simulations were performed via 3D RANS simulations using the SST k-ω turbulence model. The results show that the use of a helmet always reduces the aerodynamic drag with respect to the bare head configuration. Besides, an optimised helmet design enables a reduction of the skaters aerodynamic drag by 5.9%, with respect to the bare-head configuration, and by 1.6% with respect to the use of the baseline Omega helmet.

Aerodynamic Effects of Tie-Boss in Extremely Long Turbine Blades

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Tomáš Radnic ◽  
Jindřich Hála ◽  
Martin Luxa ◽  
David Šimurda ◽  
Jiří Fürst ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Blade Cascade ◽  
Prior Investigation ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Investigation

Focus of this paper is aerodynamic investigation of tie-boss stabilization devices for extremely long rotor blades. This investigation covered measurements on multiple blade cascades and computational fluid dynamics (CFD) simulation of the flow past these cascades. Conclusions were drawn from results of the measurements and CFD and from the knowledge of prior investigation of the used blade cascade. Main focus of this paper is to describe influence of a tie-boss stabilization device on flow field in interblade channel. Tie-boss with more massive shape proved to cause lesser losses, while tie-boss with a tailored trailing edge showed lesser influence on flow turning.

Assessing the Deposition of a Water Spray on a Plate in a Simple Box Configuration Using Computational Fluid Dynamics (CFD)

2007 ◽  
Vol 2 (3) ◽  
Author(s):  
Tim Langrish ◽  
Kashinath Kota
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Droplet Size ◽  
Cfd Simulation ◽  
Water Spray ◽  
Air Flow Rate ◽  
Cfd Simulations ◽  
Deposition Rates ◽  
Deposition Fluxes ◽  
Computational Fluid Dynamics Cfd

The deposition rates for a water spray on a plate have been studied in a rectangular box configuration to determine the effects of turbulence and droplet size in a relatively simple geometrical configuration, with the aim being to assess the ability of a CFD simulation to predict the actual wall deposition fluxes and the trends in these fluxes in such a geometry. The main air velocities that were used in this study were 1 m/s and 2 m/s inside the box. The results from the Computational Fluid Dynamics (CFD) simulations underpredicted the percentage deposition on the plate significantly (by about 75% and lower) compared with the experiments. The droplet size effects on the deposition rates were studied by varying the atomizer air pressure (air flow rate). The inlet turbulence level was changed by placing a mesh at the box inlet. The results of experiments and simulations showed similar trends when decreasing the droplet size. Increasing the turbulence intensity at the box inlet seems to result in underpredicting the actual amounts of deposition, since the movements of the fine droplets are not well predicted by RANS approaches, because the RANS approaches do not predict the gas-phase turbulence levels near the walls well. The other reasons for the underprediction in the simulations could be coalescence of droplets in the spray, dispersion of droplets due to turbulence and radial variations in droplet velocities and sizes in the spray.

scholarly journals Research on dynamic characteristics of gas film of spherical hybrid gas bearings based on computational fluid dynamics

2020 ◽  
Vol 44 (1) ◽  
pp. 23-37
Author(s):  
Chenhui Jia ◽  
Zhiwu Cui ◽  
Shijun Guo ◽  
Wensuo Ma
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Bearing Capacity ◽  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Gas Flow ◽  
Static Pressure ◽  
Gas Bearings ◽  
Gas Bearing

A realizable k–ε turbulence model for spherical spiral groove hybrid gas bearing films was established based on computational fluid dynamics (CFD). A six degrees of freedom passive grid was used to calculate the gas film pressure distribution, bearing capacity, and dynamic characteristic coefficients numerically. The gas flow field dynamic and static pressure coupling mechanism was studied. The effects of the rotation speed, gas film thickness eccentricity ratio, and gas supply pressure on the dynamic and static pressure bearing capacity, and dynamic characteristic coefficients during operation were analyzed as a method of research into the mechanical mechanisms of gas bearing stability. The CFD calculation analysis can simulate the complex gas flow in the transient flow field of the gas film and determine reasonable operation parameters to optimize the dynamic and static pressure coupling effects, which can improve the gas film bearing capacity, dynamic characteristics, and operational stability of gas bearings.

scholarly journals Using Computational Fluid Dynamics to Simulate Flow Fields from various Melt Blowing Dies

2005 ◽  
Vol os-14 (1) ◽  
pp. 1558925005os-14
Author(s):  
Holly M. Krutka ◽  
Robert L. Shambaugh ◽  
Dimitrios V. Papavassiliou
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Flow Fields ◽  
Melt Blowing ◽  
Cfd Simulations ◽  
Flow Field Characteristics ◽  
Computational Fluid Dynamics Cfd ◽  
The Common

This paper is an investigation of the flow fields generated by dual rectangular jets. Specifically, the jets examined are the same as the common slot dies used in the industrial melt blowing process. In this process, a molten polymer is attenuated by air discharging from dual jets. The velocity and turbulence of these flow fields determine the rate and quality of polymer fiber production. The flow field characteristics can be simulated quickly and efficiently using computational fluid dynamics (CFD). These CFD simulations require the use of an appropriate length scale to describe the flow field. This paper describes how these CFD simulations can be used to compare the flow fields generated by different jet geometries.

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