scholarly journals Computational Fluid Dynamics Model of Air Velocity through a Poultry Transport Trailer in a Holding Shed

2020 ◽  
Vol 36 (6) ◽  
pp. 963-973
Author(s):  
Christian L. Heymsfield ◽  
Yi Liang ◽  
Thomas A. Costello
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cooling System ◽  
Model Simulation ◽  
List Type ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Air Velocity ◽  
Space Module ◽  
Alternative Design

HighlightsComputational fluid dynamics modeling was an effective tool to simulate conditions on transport trailers in holding broilers for slaughter, to understand the performance of existing and alternative system configurations;Model simulation and measurements indicated that less than 32% of airflow generated by the cooling fans in the existing fan configuration in this study actually penetrated through the bird-occupied spaces;Simulations suggest that higher air velocity in the bird occupied zone within the modules can be achieved by alternative fan configurations at the holding shed, such as employing one fan per module, or with the addition of a transition enclosures from each fan outlet to the face of the receiving module. Abstract. The configuration of cooling systems in commercial holding sheds, where live broilers wait in cage modules for slaughter, varies between processing plants, with cooling system efficacies largely unknown. A computational fluid dynamics (CFD) model was developed to simulate airflow through cage modules in a poultry trailer in a typical holding shed configuration. Three alternative design configurations were simulated in order to better understand the air velocity profiles and to explore potential improvements for better cooling performance. Experimental data were collected within modules in a poultry trailer, parked in an existing commercial holding shed during warm summer conditions. Results from the CFD model had reasonable agreement with measured field data. Simulated air velocities were mostly within one standard deviation of measured values. Simulation of airflow through modules in the base configuration showed that less than 32% of airflow from the fans actually penetrated through the bird-occupied space. Module tiers experienced different airflow penetration due to the ad hoc positioning/alignment of the fans relative to the modules. In the base industry configuration, fans were in fixed positions and the number of fans and their centerline discharge axes did not align with the modules on the trailer. Regions not aligned with the faces of the fans, such as the uppermost and bottommost tiers, and horizontal locations offset from the fans, received the least airflow through the modules. Sections of modules experienced lower air velocity with increasing distance from the fans. Simulation of Design Alternative 2 (which added additional fans so that a fan was centered on each row) predicted an improved fan airflow of 3.08 and 3.05 kg s-1 through the cages in two adjacent rows, compared to 1.52 and 2.15 kg s-1 predicted for the original configuration. The increased air velocity using the alternative design illustrates the potential improvement and need to further optimize the design of these holding sheds. This research showed that a CFD model is an effective tool to simulate airflow conditions on poultry trailers in holding sheds to explore various holding shed cooling configurations and strategies. Keywords: Air velocity, CFD, Poultry Transportation, Poultry welfare.

Manufacturing and Computational Fluid Dynamics Modeling of a Patient-Specific Fistula Model

2017 ◽  
Author(s):  
Yang Liu ◽  
Yihao Zheng ◽  
John Pitre ◽  
William Weitzel ◽  
Joseph Bull ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Patient Specific ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Computational Fluid Dynamics Cfd ◽  
Particle Imaging ◽  
Venous Wall ◽  
Good Agreement

Arteriovenous fistula is the joining of an artery to a vein to create vascular access for dialysis. The failure or maturation of fistula is affected by the vessel wall shear stress (WSS), which is difficult to measure in clinic. A computational fluid dynamics (CFD) model was built to estimate WSS of a patient-specific fistula model. To validate this model, a silicone phantom was manufactured and used to carry out a particle imaging velocimetry (PIV) experiment. The flow field from the PIV experiment shows a good agreement with the CFD model. From the CFD model, the highest WSS (40 Pa) happens near the anastomosis. WSS in the vein is larger than that in the artery. WSS on the outer venous wall is larger than that on the inner wall. The combined technique of additive manufacturing, silicone molding, and CFD is an effective tool to understand the maturation mechanism of a fistula.

Experimental Study and Computational Fluid Dynamics Modeling of Pulp Suspensions Flow in a Pipe

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Carla Cotas ◽  
Bruno Branco ◽  
Dariusz Asendrych ◽  
Fernando Garcia ◽  
Pedro Faia ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Drop ◽  
Flow Regime ◽  
Turbulent Regime ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Transition Flow ◽  
Pulp Suspensions ◽  
Transition Flow Regime

Eucalyptus and Pine suspensions flow in a pipe was studied experimentally and numerically. Pressure drop was measured for different mean inlet flow velocities. Electrical impedance tomography (EIT), was used to evaluate the prevailing flow regime. Fibers concentration distribution in the pipe cross section and plug evolution were inferred from EIT tomographic images. A modified low-Reynolds-number k–ε turbulence model was applied to simulate the flow of pulp suspensions. The accuracy of the computational fluid dynamics (CFD) predictions was significantly reduced when data in plug regime was simulated. The CFD model applied was initially developed to simulate the flow of Eucalyptus and Pine suspensions in fully turbulent flow regime. Using this model to simulate data in the plug regime leads to an excessive attenuation of turbulence which leads to lower values of pressure drop than the experimental ones. For transition flow regime, the CFD model could be applied successfully to simulate the flow data, similar to what happens for the turbulent regime.

Polymer Electrolyte Fuel Cell Design Based on Three-Dimensional Computational Fluid Dynamics Modeling

2009 ◽  
Vol 6 (2) ◽  
Author(s):  
Stefano Cordiner ◽  
Simon Pietro Lanzani ◽  
Vincenzo Mulone ◽  
Marco Chiapparini ◽  
Angelo D’Anzi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Cooling System ◽  
Three Dimensional ◽  
Design Procedure ◽  
Operating Conditions ◽  
Polymer Electrolyte Fuel Cell ◽  
Dynamics Modeling

An entirely numerical design procedure, based on computational fluid dynamics, is introduced to evaluate the performance of different polymer electrolyte fuel cell layouts and sets of operating conditions for assigned target parameters in terms of performance. The design procedure has been applied to a coflow design, characterized by large active area (500 cm2), moderate temperature (70°C), liquid cooling, and metal supporting. The role of heat transfer between the cell and the cooling system is analyzed to properly address the influence of operating conditions on power density and flooding via a comprehensive parametric analysis.

scholarly journals A Computational Fluid Dynamics Modeling and Experimental Study of the Mixing Process for the Dispersion of the Synthetic Fibers in Wet-Lay Forming

2008 ◽  
Vol 3 (1) ◽  
pp. 155892500800300 ◽  
Author(s):  
Melur K. Ramasubramanian ◽  
Donald A. Shiffler ◽  
Amit Jayachandran
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wire Mesh ◽  
Spherical Particles ◽  
Design Parameters ◽  
Mixing Process ◽  
Cfd Model ◽  
Discrete Phase Model ◽  
Dynamics Modeling ◽  
Synthetic Fibers

In this paper, we present results from a computational fluid dynamics (CFD) model for the mixing process used to disperse synthetic fibers in wet-lay process. We used CFD software, FLUENT, together with the MIXSIM user interface to accurately model the impeller geometry. A multiple reference frame (MRF) model and standard k-e turbulence model were used to model the problem. After obtaining a converged solution for the mixing tank with water, a discrete phase model was constructed by injecting spherical particles into the flow. A mixing tank with baffles and a centrally located impeller was used in experiments. PET fibers (1.5 denier, 6.35, 12.7, and 38.7 mm) at a concentration of 0.01% were mixed in water for the study. In regions behind the baffles, where the model predicted higher concentration of particles, experimental results showed a 34% higher concentration relative to the region in the high turbulence zone near the center. Instantaneous sheets were formed by rapidly dipping and removing a flat wire mesh strainer into the tank at two different locations to assess the state of dispersion in the tank. The sheets were transferred onto a blotting paper and examined under a microscope to count defects. Results show that the number of rope defects was 43% higher in sheets drawn from the region behind the baffles than in the sheets drawn from regions near the center of the tank. Changing baffles from a rectangular to a triangular cross section decreased the number of rope defects, but increased the number of log defects in the sample sheets at the same location. The CFD model can be used to optimize mixing tank design for wet lay fiber dispersion. The model provides further insight into the mixing process by predicting the effect of changes in design parameters on dispersion quality.

Evolution of Phosphine from Aluminum Phosphide Pellets

2021 ◽  
Vol 64 (2) ◽  
pp. 615-624
Author(s):  
Sherif Elsayed ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
Mingjun Wei
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computational Model ◽  
Solid Material ◽  
Effect Of Temperature ◽  
Published Data ◽  
List Type ◽  
Limited Information ◽  
Cfd Model ◽  
Computational Fluid Dynamics Cfd

HighlightsThis study developed a mathematical relationship accounting for the production rate of phosphine.The effect of temperature on phosphine sorption into wheat is described mathematically.A computational fluid dynamics (CFD) model was built to predict the phosphine concentration in fumigated grain.Experiments were conducted to validate the CFD model.Abstract. Phosphine gas (PH3) is widely used as a fumigant for stored product insect infestations due to its relatively low price and the near absence of residual chemical on the grain. Understanding the behavior of phosphine gas inside the fumigated space is crucial to maintaining a lethal dosage and protecting stored grain from subsequent insect damage. Phosphine is available either in gas form or is produced from a solid material, as pellets or tablets, that reacts with water in the air. The solid form is the most commonly used; however, limited information is available on the rate of phosphine gas generated from the solid material. In this study, a mathematical equation was formulated, based on previous studies in the literature, to describe the gas generation rate. This equation was incorporated into a computational model using ANSYS Fluent 19.1, a commercial software for computational fluid dynamics (CFD) analysis. The computational model developed here allows prediction of the phosphine concentration within a fumigated grain bulk. The PH3 sorption was included in the model. The effect of temperature on the sorption rate was investigated based on published data, and the rate change due to temperature was characterized. The gas generated by a single pellet was measured in laboratory experiments in a 0.208 m3 sealed barrel. The measurements confirmed the CFD results with an error of 0.3%, 0.9%, and 7.2% for three different configurations. The deviations seen between the experimental replicates increased the error and show the need for further investigation of the effects of temperature, grain age and history, leakage, and other factors. Keywords: CFD, Evolution rate, Phosphine, Sorption.

scholarly journals Application of Computational Fluid Dynamics in Chlorine-Dynamics Modeling of In-Situ Chlorination Systems for Cooling Systems

2020 ◽  
Vol 10 (13) ◽  
pp. 4455
Author(s):  
Jongchan Yi ◽  
Jonghun Lee ◽  
Mohd Amiruddin Fikri ◽  
Byoung-In Sang ◽  
Hyunook Kim
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Power Plant ◽  
Power Plants ◽  
Cooling System ◽  
Low Cost ◽  
Electrochemical Process ◽  
Dynamics Modeling ◽  
Pipe Surface

Chlorination is the preferred method to control biofouling in a power plant cooling system due to its comparative effectiveness and low cost. If a power plant is located in a coastal area, chlorine can be electrochemically generated in-situ using seawater, which is called in-situ electro-chlorination; this approach has several advantages including fewer harmful chlorination byproducts and no need for chlorine storage. Nonetheless, this electrochemical process is still in its infancy in practice. In this study, a parallel first-order kinetics was applied to simulate chlorine decay in a pilot-scale cooling system. Since the decay occurs along the water-intake pipe, the kinetics was incorporated into computational fluid dynamics (CFD) codes, which were subsequently applied to simulate chlorine behavior in the pipe. The experiment and the simulation data indicated that chlorine concentrations along the pipe wall were incremental, even under the condition where a strong turbulent flow was formed. The fact that chlorine remained much more concentrated along the pipe surface than in the middle allowed for the reduction of the overall chlorine demand of the system based on the electro-chlorination. The cooling system, with an in-situ electro-chlorination, consumed only 1/3 of the chlorine dose demanded by the direct injection method. Therefore, it was concluded that in-situ electro-chlorination could serve as a cost-effective and environmentally friendly approach for biofouling control at power plants on coastal areas.

scholarly journals 3D computational fluid dynamics modeling of temperature and humidity in a humidified greenhouse

2021 ◽  
Vol 13 (1) ◽  
pp. 17-31
Author(s):  
Cuauhtémoc Pérez-Vega ◽  
◽  
José Armando Ramírez-Arias ◽  
Irineo L. López-Cruz ◽  
Ramón Arteaga-Ramírez ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Ventilation ◽  
Temporal Distribution ◽  
Cfd Modeling ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Temperature And Humidity ◽  
Humidity Measurements ◽  
Computational Fluid Dynamics Cfd

Introduction: Medium and low technology greenhouses use natural ventilation as a method of temperature and humidity control. However, at certain times of the year, this is insufficient to extract excess heat inside the greenhouse, so devices such as hydrophanes (humidifiers) have been implemented to reduce the temperature. It is necessary to know the behavior of temperature and humidity, since both factors influence the development of crops and, therefore, their yield. Objective: To develop a computational fluid dynamics (CFD) model of a naturally ventilated zenithal greenhouse equipped with hydrophanes to understand the spatial and temporal distribution of temperature and humidity inside the greenhouse. Methodology: The experiment was carried out in a greenhouse equipped with hydrophanes and grown with bell pepper. Temperature and humidity measurements were performed from March 7 to 25, 2014. The ANSYS Workbench program was used for the 3D CFD modeling. Results: The CFD model satisfactorily described the temperature and humidity distribution of the greenhouse, with an error of 0.11 to 3.43 °C for temperature, and 0.44 to 10.80 % for humidity. Limitations of the study: Numerical modeling using CFD is inadequate to model the temporality of the variables. Originality: There are few studies that model humidity behavior with CFD and the use of hydrophanes in Mexico. Conclusions: The CFD model allowed visualizing the distribution of temperature and air humidity inside the greenhouse.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

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