scholarly journals An Investigation of the Flow Distribution Inside a Radial Sidestream Inlet of a Centrifugal Compressor

2000 ◽  
Author(s):  
Zheji Liu ◽  
D. Lee Hill ◽  
Gary Colby
Keyword(s):  
Test Data ◽  
Centrifugal Compressor ◽  
Flow Distribution ◽  
Production Test ◽  
Cfd Model ◽  
Cfd Models ◽  
Multi Stage ◽  
Final Design ◽  
Computational Fluid Dynamics Cfd ◽  
Return Channel

A radial sidestream inlet is commonly utilized in multi-stage centrifugal compressors to introduce additional gas into the mid-stage of the compressor. The flow distribution after the junction of the sidestream and the main return channel of the upstream stage can significantly affect the performance of the next stage. In this study, the mixing between the fluid from the sidestream component and the fluid from the main return channel was investigated numerically using Computational Fluid Dynamics (CFD). A variety of CFD models of different geometry, different boundary conditions, and different grid density were developed to analyze the uniformity of the flow entering the impeller of the next stage. The flow distribution difference between the sidestream CFD model and the CFD model with the sidestream coupled to the main return channel suggests that both the return channel and the sidestream have to be modeled together to get meaningful results. The results of this effort were used in conjunction with production test data to help resolve a performance shortfall of a multi-stage centrifugal compressor with sidestream injection. The test data from the final design is also provided to show the resulting improvement in head rise.

scholarly journals A Study on Microscale Wind Simulations with a Coupled WRF–CFD Model in the Chongli Mountain Region of Hebei Province, China

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 731
Author(s):  
Shaohui Li ◽  
Xuejin Sun ◽  
Shan Zhang ◽  
Shijun Zhao ◽  
Riwei Zhang
Keyword(s):  
Wind Field ◽  
Complex Terrain ◽  
Wrf Model ◽  
Mountain Region ◽  
Weather Research And Forecasting ◽  
Cfd Model ◽  
Improved Method ◽  
Comprehensive Understanding ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd

To ensure successful hosting of the 2022 Olympic Winter Games, a comprehensive understanding of the wind field characteristics in the Chongli Mountain region is essential. The purpose of this research was to accurately simulate the microscale wind in the Chongli Mountain region. Coupling the Weather Research and Forecasting (WRF) model with a computational fluid dynamics (CFD) model is a method for simulating the microscale wind field over complex terrain. The performance of the WRF-CFD model in the Chongli Mountain region was enhanced from two aspects. First, as WRF offers multiple physical schemes, a sensitivity analysis was performed to evaluate which scheme provided the best boundary condition for CFD. Second, to solve the problem of terrain differences between the WRF and CFD models, an improved method capable of coupling these two models is proposed. The results show that these improvements can enhance the performance of the WRF-CFD model and produce a more accurate microscale simulation of the wind field in the Chongli Mountain region.

3-D periodic CFD model of the heating system in a coke oven battery

2014 ◽  
Vol 24 (4) ◽  
pp. 891-906 ◽  
Author(s):  
Jacek Smolka ◽  
Adam Fic ◽  
Andrzej J. Nowak ◽  
Ludwik Kosyrczyk
Keyword(s):  
Coke Oven ◽  
Heating System ◽  
Cfd Model ◽  
Gas Combustion ◽  
Content Type ◽  
Cfd Models ◽  
Steady State Operation ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd ◽  
Periodic Heat

Purpose – The purpose of this paper is to develop a 3-D fully transient numerical model of the heat and fluid flow associated with the chemical reactions that occur in the heating system of the coke oven battery. As a result, the model can be used to provide data for the control system of the battery to reduce energy consumption and emissions and to obtain a product of the desired quality. Design/methodology/approach – In the proposed model, an accurate representation of the heating flue geometry, the volumetric heat sources as a result of the coke oven gas combustion, the temperature- and mole fraction-dependent properties of the gases were taken into account. The most important part of the model was the unsteady boundary condition definition that allowed the modeling of the periodic heat delivery to the two oven heating walls, both in the coking and the reversion cycles. Findings – The temperatures obtained using the computational fluid dynamics (CFD) model showed the same pattern of temperature variations as that observed in the experiments. It was also found that the quality of the temperature variation predictions was highly dependent on the radiation model settings. Originality\value – The CFD models available in the literature describe the steady or pseudo-steady state operation of the heating system of the coke oven battery. The model developed in this work fully reflects the unsteady character of this heating system. Moreover, the proposed model is prepared for coupling with a model of the coking process that occurs in the two neighboring coke oven chambers.

scholarly journals Computational modeling of fire safety in metro-stations

2021 ◽  
Author(s):  
Philip McKeen
Keyword(s):  
Fire Safety ◽  
Performance Based Design ◽  
Cfd Model ◽  
Fire Dynamics ◽  
Evacuation Modeling ◽  
Fire Dynamics Simulator ◽  
Cfd Models ◽  
Smoke Spread ◽  
Modeling Software ◽  
Computational Fluid Dynamics Cfd

This research investigates and attempts to quantify the hazards associated with fire in metrostations. The use of numerical simulations for the analysis of fire safety within metro-stations allows for the prediction and analysis of hazards within the built environment. Such approaches form the growing basis of performance based design (PBD), which can optimize design solutions. The simulations utilize Fire Dynamics Simulator (FDS), a Computational Fluid Dynamics (CFD) model and Pathfinder, an evacuation modeling software. The safety of underground metro-stations is analyzed through the simulation of smoke spread and egress modelling. CFD models of TTC’s Union Station and TransLink’s Yaletown Station are developed to allow for simulations of smoke spread scenarios. These models are evaluated in regards to the preservation of tenability and influence on the Available Safe Egress Time (ASET). The egress of metro-stations is modelled and analyzed to determine the Required Safe Egress Time (RSET).

Impact of Heat Transfer on Contaminant Dispersion in a Public Building

2006 ◽  
Author(s):  
Sue Ellen Haupt ◽  
Robert F. Kunz ◽  
L. Joel Peltier ◽  
James J. Dreyer ◽  
Howard J. Gibeling
Keyword(s):  
Thermal Effects ◽  
Building Materials ◽  
Time Of Day ◽  
Thermal Coupling ◽  
Cfd Model ◽  
Thermal Heating ◽  
Contaminant Dispersion ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

Computational fluid dynamics (CFD) models are effective at predicting dispersion of contaminants in or near a building. It is well known that thermal effects impact the flow around and within structures. This study assesses the importance of time of day, building materials, sky cover, etc. on the local thermal heating of a building. All these features affect the buoyancy, and thus, the resulting flow and dispersion about and inside a building. This study examines that impact through including full thermal coupling with flow calculations for an environmentally friendly building, including thermal radiation, conduction, and convection effects with a CFD model for both the interior and exterior of a building. The emphasis here is on simulating the impact of heating on contaminant dispersion.

scholarly journals A New Device used in Selective Withdrawal from Reservoirs and its Effectiveness Verified in Computational Fluid Dynamics

2018 ◽  
Vol 14 (03) ◽  
pp. 142
Author(s):  
Jinsuo Lu ◽  
Wei Zhang ◽  
Dengyu Wang ◽  
Xiaoyi Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Layer Thickness ◽  
Water Intake ◽  
Flow Distribution ◽  
Water Layer ◽  
Cfd Model ◽  
Selective Withdrawal ◽  
New Device ◽  
Computational Fluid Dynamics Cfd

<p class="16">Water intake with fixed height limits the application of selective withdrawal technology in a certain degree. This study proposes a technological idea to install baffles on water intake. Through the rotation of upper and lower baffle, poor water layer can be blocked. A Computational Fluid Dynamics (CFD) model for the upper baffle on water intake is constructed. The results show that the baffle installed on the upper part of orifice can reduce the withdrawal layer thickness and flow on the upper part of orifice centre. Thereby, the withdrawal flow on lower part can be indirectly increased. While, baffle length and inclining angle are the important factors to influence the withdrawal layer thickness and flow distribution. Therefore, the adjusting range of selective withdrawal can be economically enhanced by installing baffles on water intake.</p>

scholarly journals Computational modeling of fire safety in metro-stations

2021 ◽  
Author(s):  
Philip McKeen
Keyword(s):  
Fire Safety ◽  
Performance Based Design ◽  
Cfd Model ◽  
Fire Dynamics ◽  
Evacuation Modeling ◽  
Fire Dynamics Simulator ◽  
Cfd Models ◽  
Smoke Spread ◽  
Modeling Software ◽  
Computational Fluid Dynamics Cfd

This research investigates and attempts to quantify the hazards associated with fire in metrostations. The use of numerical simulations for the analysis of fire safety within metro-stations allows for the prediction and analysis of hazards within the built environment. Such approaches form the growing basis of performance based design (PBD), which can optimize design solutions. The simulations utilize Fire Dynamics Simulator (FDS), a Computational Fluid Dynamics (CFD) model and Pathfinder, an evacuation modeling software. The safety of underground metro-stations is analyzed through the simulation of smoke spread and egress modelling. CFD models of TTC’s Union Station and TransLink’s Yaletown Station are developed to allow for simulations of smoke spread scenarios. These models are evaluated in regards to the preservation of tenability and influence on the Available Safe Egress Time (ASET). The egress of metro-stations is modelled and analyzed to determine the Required Safe Egress Time (RSET).

Modeling of High Temperature Gas Flow 3D Distribution in BF Throat Based on the Computational Fluid Dynamics

2015 ◽  
Vol 19 (2) ◽  
pp. 269-276 ◽  
Author(s):  
Jian Qi An ◽  
◽  
Kai Peng ◽  
Wei Hua Cao ◽  
Min Wu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Flow ◽  
Numerical Solutions ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Cfd Model ◽  
Ansys Fluent ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd

This paper aims at building a Computational Fluid Dynamics (CFD) model which can describe the gas flow three dimensions (3D) distribution in blast furnace (BF) throat. Firstly, the boundary conditions are obtained by rebuilding central gas flow shape in BF based on computer graphics. Secondly, the CFD model is built based on turbulent model by analyzing the features of gas flow. Finally, a method which can get the numerical solutions of the model is proposed by using CFD software ANSYS/FLUENT. The proposed model can reflect the changes of the gas flow distribution, and can help to guide the operation of furnace burdening and to ensure the BF stable and smooth production.

Cluster of High-Powered Racks Within a Raised-Floor Computer Data Center: Effect of Perforated Tile Flow Distribution on Rack Inlet Air Temperatures

2004 ◽  
Vol 126 (4) ◽  
pp. 510-518 ◽  
Author(s):  
Roger Schmidt ◽  
Ethan Cruz
Keyword(s):  
Data Center ◽  
Control Volume ◽  
Flow Distribution ◽  
Computer Code ◽  
Cfd Model ◽  
Computer Data ◽  
Air Temperatures ◽  
Finite Control ◽  
Computational Fluid Dynamics Cfd ◽  
Tile Flow

This paper focuses on the effect on rack inlet air temperatures as a result of maldistribution of airflows exiting the perforated tiles located adjacent to the fronts of the racks. The flow distribution exiting the perforated tiles was generated from a computational fluid dynamics (CFD) tool called Tileflow (trademark of Innovative Research, Inc.). Both raised floor heights and perforated tile-free areas were varied in order to explore the effect on rack inlet temperatures. The flow distribution exiting the perforated tiles was used as boundary conditions to the above-floor CFD model. A CFD model was generated for the room with electronic equipment installed on a raised floor. Forty racks of data processing (DP) equipment were arranged in rows in a data center cooled by chilled air exhausting from perforated floor tiles. The chilled air was provided by four A/C units placed inside a room 12.1 m wide×13.4 m long. Because the arrangement of the racks in the data center was symmetric, only half of the data center was modeled. The numerical modeling for the area above the raised floor was performed using a commercially available finite control volume computer code called Flotherm (trademark of Flomerics, Inc.). The flow was modeled using the k-e turbulence model. Results are displayed to provide some guidance on the design and layout of a data center.

scholarly journals Partial integration of ADM1 into CFD: understanding the impact of diffusion on anaerobic digestion mixing

2020 ◽  
Vol 81 (8) ◽  
pp. 1658-1667 ◽  
Author(s):  
Yohannis Mitiku Tobo ◽  
Usman Rehman ◽  
Jan Bartacek ◽  
Ingmar Nopens
Keyword(s):  
Anaerobic Digestion ◽  
Homogeneous Distribution ◽  
Cfd Model ◽  
Homogeneity Analysis ◽  
Cfd Models ◽  
Mode Of Operation ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Proper Performance ◽  
Partial Integration

Abstract Sufficient mixing is crucial for the proper performance of anaerobic digestion (AD), creating a homogeneous distribution of soluble substrates, biomass, pH, and temperature. The opaqueness of the sludge and mode of operation make it challenging to study AD mixing experimentally. Therefore, hydrodynamics modelling employing computational fluid dynamics (CFD) is often used to investigate this mixing. However, CFD models mostly do not include biochemical reactions and, hence, ignore the effect of diffusion-induced transport on AD heterogeneity. The novelty of this work is the partial integration of Anaerobic Digestion Model no. 1 (ADM1) into the CFD model. The aim is to better understand the effect of advection–diffusion transport on the homogenization of soluble substrates and biomass. Furthermore, AD homogeneity analysis in terms of concentration distribution is proposed rather than the traditional velocity distributions. The computed results indicate that including diffusion-induced transport affects the homogeneity of AD.

Aerodynamic Optimisation of a Centrifugal Compressor Return Channel and U-Turn With Genetic Algorithms

2011 ◽  
Author(s):  
A. Hildebrandt
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Loss ◽  
Kriging Model ◽  
Navier Stokes ◽  
Cross Sectional ◽  
Pressure Loss Coefficient ◽  
Multi Stage ◽  
Evolutionary Optimisation ◽  
Return Channel ◽  
Set Up

This paper presents the numerical analysis and aerodynamic optimisation of a return channel system and U-turn for multi stage single shaft centrifugal compressor machinery. An optimisation program is used, based on an OpenSource 3D viscous Navier Stokes Solver and an OpenSource evolutionary optimisation algorithm. The coupling between the Navier Stokes flow solver and the evolutionary algorithm is direct, without any meta-model such as ANN (Artificial Neural Network) or a Kriging model. Two different U-turn geometries — based on two different flow inlet profiles — are optimised, analysed and finally coupled to a return channel blade geometry, which is optimised itself. The optimisation of the return channel blade has been set up in two different ways, once with parallel meridional hub and shroud walls and once with a non-parallel optimised meridional shroud contour line. Results show a reduction of total pressure loss by 3% for the optimised blade shapes compared to a standardised blade shape of constant change of tangential momentum. A significant reduction in pressure loss coefficient from 0.825 to 0.627 could be achieved by the optimisation of the meridional contour lines of the return channel. Furthermore, the effect of non-sufficient cross -sectional area at the return channel trailing edge on the overall performance is presented.

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