scholarly journals Analysis of Thermally Controlled Poultry Housing Using CFD

2020 ◽  
pp. 40-48
Author(s):  
T. O. Tehinse ◽  
F. R. Falayi ◽  
T. O. Aduewa ◽  
M. O. Alatise ◽  
B. I. Osho
Keyword(s):  
Room Temperature ◽  
Solid Wall ◽  
Air Flow ◽  
Critical Time ◽  
Pressure Profile ◽  
Housing System ◽  
Data Logger ◽  
Air Velocity ◽  
External Temperature ◽  
Temperature Levels

Poultry industry’s development in the past two decades and the need for increased animal protein sources in the hot regions of the world, require the need to develop housing system that is thermally controlled for optimal production. The research was carried out at Federal University of Technology Akure, Ondo State, Nigeria. The facility consisted of a broiler house of 6 rooms enclosed by masonry sidewalls at the base and insulated plywood at the upper section of the house with each experimental room equipped with blower, suction fan and heater. The data were monitored at the most critical time of the day – 1 pm during the dry season. Experimental data were recorded using developed and calibrated data logger. The 5 experimental rooms are programed to 5 temperature levels (41, 38, 35, 32 and 29°C) characterizing extreme heat boundary conditions for broilers with fans programmed at 1.5 m/s air velocity. The aim of this study is to evaluate the thermal distribution in solid-wall broiler houses using computational fluid dynamics (CFD). The CFD technique allows visualizing air flow according to different running condition for each room for exhaust fans, as well as other parameters. The simulation was used to determine the air temperature variation, inner wall temperature, external temperature, air velocity distribution, external wall heat flux, pressure and wall heat transfer coefficient in all the experimental rooms of poultry house. The simulated air flow pattern and temperature distribution in the experimental rooms were analyzed and the result revealed increase room temperature as the preset room temperature increases. However, the velocity profile in all the room shows buildup of air at the outlet vent due to turbulence created by the suction fans. The pressure profile across the rooms was relatively the same.

Effect of Reactant Preheating on the Stability of Non-Premixed Methane/Air Flames

2010 ◽  
Author(s):  
Sylvain Lamige ◽  
Ce´dric Galizzi ◽  
Jiesheng Min ◽  
Julien Perles ◽  
Fre´de´ric Andre´ ◽  
...  
Keyword(s):  
Room Temperature ◽  
Initial Temperature ◽  
Flame Stability ◽  
Air Velocity ◽  
Lifted Flames ◽  
Local Extinctions ◽  
Lift Off ◽  
Temperature Levels ◽  
The Stability ◽  
Jet Velocities

This study details the influence of reactant temperature on the stability of non-premixed CH4/air co-flow jet flames. Flame characteristics have been studied for five temperature levels (from 295 K to 600 K). The hysteresis zone formed by the limits between attached and lifted flame translates towards higher methane jet velocities with an increase of initial temperature, independently of the air velocity range. Moreover, critical velocities vary linearly with initial temperature. In addition, attachment and lift-off heights have been obtained from CH* chemiluminescence visualization. Results point out that the attachment height decreases significantly with temperature. Observations also indicate that the intrinsic process of lifting is modified. Pre-lifting anchored flame local extinctions, not observed at room-temperature, appear at higher initial temperatures; their occurrence increases with temperature. The lift-off height of turbulent lifted flames is also reduced with temperature. Overall, results show that increasing local temperature in the stabilization zone enhances flame stability.

Irradiation and Temperature Effects on Anti-Foam Agent Performance in a Non-Newtonian Waste Slurry Simulant

2009 ◽  
Author(s):  
Hector N. Guerrero ◽  
Mark D. Fowley ◽  
David J. Sherwood
Keyword(s):  
High Temperature ◽  
Temperature Effects ◽  
Room Temperature ◽  
National Laboratory ◽  
Air Flow ◽  
Savannah River ◽  
Polydimethyl Siloxane ◽  
Air Velocity ◽  
Bench Scale ◽  
Savannah River National Laboratory

Foaming tests were performed in a bench-scale foam column and 1/9th-scale mechanically-agitated mixing system at the Savannah River National Laboratory (SRNL) for a simulant of waste slurry from the Hanford Tank 241-AZ-101. This featured additions of DOW Corning Q2-3183A antifoam agent (AFA) to prevent foaming, especially in the evaporators. These waste slurries (typically 15 wt% solids) are particularly prone to particle-stabilized foaming. Previous studies have shown that up to 20% of the polydimethyl siloxane (PDMS) portion of the AFA mixture is degraded by radiation. The high temperature (90°C) for 48 hrs of a caustic leaching process may have a similar effect on the polymer. The objective of this study was to determine how well degraded AFA works. Key results are that: • Without addition of this AFA, the 1/9th-scale system had about 100% foaming at 1 mm/s air velocity and the bench-scale system had over 400% foaming for an air flow of 10 mm/s. • The effect of irradiating 350 ppm AFA was to increase foaming from 6% to 30% in the foam column and 7.6% to 13.7% in the 1/9th-scale system at an air flow of 1 mm/s at room temperature. • The effect of heating the AFA to 90°C was to increase foaming by a factor of 1.6 in the foam column. But while the effectiveness of the irradiated AFA was reduced, it still provided a significant reduction in foaming. AFA additions required to mitigate the combined effects of high temperature and radiation were also determined.

scholarly journals Contribution to the Sustainability of Agricultural Production in Greenhouses Built on Slope Soils: A Numerical Study of the Microclimatic Behavior of a Typical Colombian Structure

2021 ◽  
Vol 13 (9) ◽  
pp. 4748
Author(s):  
Edwin Villagran ◽  
Carlos Bojacá ◽  
Mohammad Akrami
Keyword(s):  
Latin American ◽  
Crop Yields ◽  
Numerical Study ◽  
Air Flow ◽  
Research Work ◽  
Flow Patterns ◽  
Soil Conditions ◽  
Air Velocity ◽  
The Hours ◽  
Microclimatic Conditions

The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 °C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out.

Temperature Distribution of Hot Air Flow in Heating Zone for Drying Application

2014 ◽  
Vol 627 ◽  
pp. 153-157
Author(s):  
Nawadee Srisiriwat ◽  
Chananchai Wutthithanyawat
Keyword(s):  
Temperature Distribution ◽  
Air Temperature ◽  
Power Supply ◽  
Air Flow ◽  
Heating Zone ◽  
Velocity Control ◽  
Rectangular Duct ◽  
Air Velocity ◽  
Hot Air ◽  
Set Up

The temperature distribution of hot air flow in heating zone of a rectangular duct has been investigated for drying application. The experimental set-up consists of a heater and a fan to generate the hot air flow in the range of temperature from 40 to 100°C and the range of air velocity between 1.20 and 1.57 m/s. An increase of the heater power supply increases the hot air temperature in the heating zone while an increase of air velocity forced by fan decreases the initial temperature at the same power supply provided to generate the hot air flow. The temperature distribution shows that the hot air temperature after transferring through air duct decreases with an increase of the length of the rectangular duct. These results are very important for the air flow temperature and velocity control strategy to apply for heating zone design in the drying process.

scholarly journals Swirler geometry effects (dh/do ratio) on synthetic gas flames: Part 1: Combustion and emission characteristics

Energetika ◽  
2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Harun Yilmaz ◽  
Omer Cam ◽  
Ilker Yilmaz
Keyword(s):  
Room Temperature ◽  
Swirling Flow ◽  
Pollutant Emissions ◽  
Emission Characteristics ◽  
Atmospheric Conditions ◽  
Data Logger ◽  
Swirl Number ◽  
Synthetic Gas ◽  
Performance Results ◽  
The City

Swirling flows increase combustion performance via favouring flame stability, pollutant emissions, and combustion intensity. The strength of a swirling flow is characterized by a parameter known as swirl number, which is highly related to the dh/do ratio. In this study, effects of the swirler dh/do ratio on combustion and emission characteristics of the synthetic gas flames of premixed 20%CNG/30%H2/30%CO/20%CO2 mixture were experimentally investigated in a laboratory-scale swirl stabilized combustor. For this purpose, twelve different swirl generators were designed and manufactured. dh/do ratios of these swirlers were set as 0.30 and 0.50, and the geometric swirl number was varied between the values of 0.4 and 1.4 (at 0.2 intervals). All experiments were conducted at a fuel-lean equivalence ratio (ϕ = 0.6), room temperature, and local atmospheric conditions of the city of Kayseri, Turkey. A data logger was utilized to plot axial and radial temperatures and NOx, CO, and CO2 profiles, which were exploited to assess combustion and emission performance. Results showed that the dh/do ratio had a non-monotonic effect on the behaviour of combustion and emission of the tested synthetic gas mixture. Depending on the swirl number, increments and decrements were observed in temperature and emission values.

scholarly journals Automobile Radiator’s Engineering and Analysation

2020 ◽  
Vol 9 (5) ◽  
pp. 554-558
Keyword(s):  
Flow Rate ◽  
Heat Dissipation ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Air Flow ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Cooling Fan

The shape of a radiator cover is crucial either in determining the pattern of air flow or in increasing the same through the radiator core thereby increasing the thermal efficiency, thus making it a necessity to understand it. Moreover the parts circumjacent to the core namely the upper tank, lower tank, cooling fan, fins, tubes, etc promote the air flow rate. Also it is to note that the air flow rate of discharge gases from radiator core is one of the prime factors in determining the automobile cooling system. Initially factors such as temperature, pressure, air flow rate that affect the performance are obtained in order to derive out the entities of operation. One of the observations that can be made through this paper is that as the volume of the coolant increases, the rate of heat dissipation increases, also parameters like inlet temperature and volume flow rate of coolant, air velocity, temperature drop and drop in pressure of coolant are factors that contribute in radiator performance evidently.

Air Flow Analysis in Square Duct Bend

2014 ◽  
Vol 695 ◽  
pp. 622-626 ◽  
Author(s):  
Mohamad Nor Musa ◽  
Mohd Nurul Hafiz Mukhtar
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Cross Section ◽  
Air Flow ◽  
Flow Analysis ◽  
Maximum Velocity ◽  
Maximum Pressure ◽  
Air Velocity ◽  
Square Duct ◽  
Inlet Velocity

This paper present new result for experimental analysis of air flow velocity and pressure distributions between two ducts bend: (1) 90° duct bend with a single turning vane having 0.03m radius and (2) 90° duct bend with double turning vane, in 0.06 × 0.06 m duct cross section. The experiment used five different Reynolds numbers chosen between the ranges 1 ×104 and 6×104. Each experiment has four point measurements: (1) point 1 and point 2 at cross section A-A and (2) point 3 and point 4 at cross section B-B. The first experimental study used single turning vane radius 0.03m with inlet air velocity from 2.5m/s to 12.2m/s. And for the second experiment that used square turning vane with 0.03m radius. In experiment 2, the inlet air velocity also start from 2.5m/s to 12.2m/s. From analysis results, the pressure drop in experiment 1 is higher than experiment 2. As example the maximum pressure drop at 7.5m/s inlet air velocity between point 1 and 3 was found to be 71.6203 Pa in experiment 1 as compared to 61.8093 Pa in experiment 2. The velocity after duct bend is greater when using double turning vane compare used single turning vane as maximum velocity at point 3 in experiment 2 compare to velocity at point 3 in experiment 1 that is 55.677× 10-4 m/s and 54.221× 10-4 m/s. The velocity at duct wall is equal to zero. When increase the value of Reynolds number or inlet velocity, the maximum velocity and total pressure also increase. For example in experiment 1 at point 1, the velocity is 48.785 × 10-4 m/s at Reynolds number 1 ×104 and velocity 65.115×10-4 m/s at Reynolds number 12.2 ×104 . Velocity flow in duct section are lower than inlet velocity. In experiment 1, the inlet velocity is 2.5m/s meanwhile the maximum velocity in the duct section at point 2 is 73.075×10-4 m/s that is much more lower than inlet velocity.

Numerical Modeling of Air Flow in a Cabinet Dryer Equipped by Deflector Plates

2019 ◽  
Vol 15 (10) ◽  
Author(s):  
Omid Reza Roustapour ◽  
Hamid Reza Gazor ◽  
Kazemi Farzin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Modeling ◽  
Air Flow ◽  
Outlet Temperature ◽  
Governing Equations ◽  
Air Velocity ◽  
Drying Time ◽  
Elapsed Time ◽  
Quadrilateral Elements ◽  
Simulation Results

AbstractIn this study, air deflector plates were used in order to increase the air elapsed time in the chamber. The air flow pattern was simulated using computational fluid dynamics. The geometry of the chamber was produced in 2D and meshed by triangular and quadrilateral elements, boundary conditions were defined and the governing equations solved. Modeling of flow without any deflectors depicted the air flowed to the chamber conducted to the outlet without any distortion. Air vortices were generated when the deflectors defined in model. To evaluate the influence of deflectors on drying period, constructed plates installed in the dryer chamber and melon slices were dried when deflectors used or not. Simulation results showed magnitude of the air velocity was increased and temperature uniform distribution developed on the surface of trays. The outlet temperature was also decreased up to 10 % and drying time reduced to 22 % when the deflectors were employed.

scholarly journals Modelling particle movement in conical guide of seeder pneumatic pipe

2020 ◽  
Vol 175 ◽  
pp. 12019
Author(s):  
Vladimir Zaitsev ◽  
Artem Kravtsov ◽  
Vladimir Konovalovi
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Air Flow ◽  
Force Analysis ◽  
Particle Movement ◽  
Air Velocity ◽  
Finite Element Calculations ◽  
Calculation Results ◽  
Case Part ◽  
Good Agreement

In the course of the study, methods for ensuring the centeringof particlesofbulkmaterialintheairflowmovinginthepneumaticductofthe seeder were investigated. To solve this problem, it is proposed to use a conical confusor. The aim of the study was to obtain the functional dependences of the movement of particles in a conical airflow guide (confusor) for the conditions of transportation of the sown particles on the basis of force analysis and to identify the nature of the movement of the sownparticlesinataperingairflow.Duringthestudy,todescribethemotion of particles in a vertical tapering pipe, a system of expressions was substantiated. The developed mathematical model of particle motion in a conical air flow, implemented in the MathCAD mathematical package, allowscalculatingboththeparticletrajectoryandthevelocityparametersof the air flow and the particles to be sown. The digital calculation results in the MathCAD program are in good agreement with the finite element calculations. The magnitude of the error in air velocity is less than 1%. The differences in the velocities of the transported particles in the calculation options do not exceed 7%. The installation of a conical guide helps tofocus the flow of particles in the central part of the narrowed air line. In this case, part of the particles in the central part of the guide will retain the initial longitudinaltrajectory.Theangleattheapexoftheconeandtheparameters of the particles affect the speed and angle of the tangent contact of the particle with theguide.

scholarly journals Three-Dimensional CFD Modelling and Analysis of the Thermal Entrainment in Open Refrigerated Display Cabinets

2008 ◽  
Author(s):  
Pedro Dinis Gaspar ◽  
L. C. Carrilho Gonc¸alves ◽  
R. A. Pitarma
Keyword(s):  
Air Temperature ◽  
Mass Flow ◽  
Air Flow ◽  
Three Dimensional ◽  
Food Products ◽  
Ambient Air ◽  
Air Velocity ◽  
Air Curtain ◽  
Numerical Predictions ◽  
Thermal Entrainment

This study presents a three-dimensional Computational Fluid Dynamics (CFD) simulation of the air flow pattern and the temperature distribution in a refrigerated display cabinet. The thermal entrainment is evaluated by the variations of the mass flow rate and thermal power along and across the air curtain considering the numerical predictions of abovementioned properties. The evaluation on the ambient air velocity for the three-dimensional (3D) effects in the pattern of this type of turbulent air flow is obtained. Additionally, it is verified that the longitudinal air flow oscillations and the length extremity effects have a considerable influence in the overall thermal performance of the equipment. The non uniform distribution of the air temperature and velocity throughout the re-circulated air curtain determine the temperature differences in the linear display space and inside the food products, affecting the refrigeration power of display cabinets. The numerical predictions have been validated by comparison with experimental tests performed in accordance with the climatic class n.° 3 of EN 441 Standard (Tamb = 25 °C, φamb = 60%; νamb = 0,2 m s−1). These tests were conducted using the point measuring technique for the air temperature, air relative humidity and air velocity throughout the air curtain, the display area of conservation of food products and nearby the inlets/outlets of the air mass flow.

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