scholarly journals EXPERIMENTAL RESEARCH ON THE DISTRIBUTION OF AIR STREAM VELOCITY USING THE TWO-LEVEL CYCLONE / EKSPERIMENTINIAI ORO SRAUTO GREIČIŲ PASISKIRSTYMO DVIEJŲ LYGIŲ CIKLONE TYRIMAI

2013 ◽  
Vol 5 (4) ◽  
pp. 330-336 ◽  
Author(s):  
Egidijus Baliukas ◽  
Pranas Baltrėnas
Keyword(s):  
Air Flow ◽  
Solid Particles ◽  
Maximum Speed ◽  
Stream Velocity ◽  
Velocity Measurements ◽  
Air Velocity ◽  
Air Volume ◽  
Air Stream ◽  
Before And After ◽  
Air Speed

In order to properly analysethe operation of a two-level multichannel cyclone,a studyon how air flow moves inside the cyclone is necessary. The two-level multichannel cyclone is designed to separate solid particles from the air stream andhas been built in the Environmental Protection Laboratory at Vilnius Gediminas Technical University. Researches on findinghow theair flow distributes withintwo levels and channels of the six-channel cyclone were made. Air velocity was measured using multimeter Testo–400 and dynamic Pito tube. Air velocity measurements in ducts before and after thedevice were done using an anemometer. The results showed that the air volume at both cyclone levels wereequal, and air velocity inthe channels that werethe same at both levels was also distributed equally. The highest air speed was measured at the end of the last IV channel and reached 13 m/s. Minimum air velocity can be observed when the rings are arranged in such way that 75% of the air flow returns to the previous channel, and the maximum speed is when the previous channel returns 25% of the air flow. Article in Lithuanian. Santrauka Siekiant tinkamai išanalizuoti dviejų lygių daugiakanalio ciklono veikimą būtina išnagrinėti valomo oro srauto judėjimą. Šis įrenginys skirtas kietosioms dalelėms iš oro srauto valyti. Daugiakanalis dviejų lygių ciklonas sukurtas ir pastatytas Vilniaus Gedimino technikos universiteto Aplinkos apsaugos laboratorijoje. Tyrimais siekiama nustatyti oro srauto pasiskirstymą dviejuose šešiakanalio ciklono lygiuose bei kanaluose. Oro greičiams kanaluose nustatyti naudojamas daugiafunkcis matuoklis Testo-400 ir dinaminis Pito vamzdelis. Oro srauto greičiams matuoti ortakiuose prieš ir už įrenginio naudojamas sparninis anemometras. Rezultatai rodė, kad į abu ciklone įrengtus lygius patenka vienodas oro tūris, ir greičiai šių lygių kanaluose pasiskirsto vienodai. Didžiausias greitis – 13 m/s užfiksuotas paskutiniojo kanalo pabaigoje. Mažiausi oro greičiai kanaluose esti, kai žiedai sudėti taip, kad 75 % oro srauto grįžtų į ankstesnį kanalą, o didžiausias greitis yra tada, kai į ankstesnį kanalą grįžta 25 % oro srauto.

scholarly journals AIR VELOCITY PROFILES IN AIR BLAST FREEZERS FILLED WITH BOXES OF FRUIT PULP MODELS

2004 ◽  
Vol 3 (2) ◽  
pp. 127
Author(s):  
J.V. Resende ◽  
V. Silveira Jr.
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Freezing Process ◽  
Fruit Pulp ◽  
Air Flow Rate ◽  
Velocity Measurements ◽  
Air Velocity ◽  
Operation Conditions ◽  
Air Stream ◽  
Pass Through

The changes in the air velocities caused by the resistance for the air flow due to fruit pulp model packaged (100 grams) and conditioned in multi layers boxes during freezing process were evaluated and air flow rate were estimated using a method of treatment of the experimental data. The air velocities were measured before the air pass through the pillage of multi layer boxes in the air stream. For the measurements processing was used a non linear regression routine. Air flow rate measured by the present method resulted of the numerical integration of air velocities adjusted profile. Results presented a relative difference 10 % higher than the standard average procedure, which consists in averaging the air velocity measurements performed at each point of the section. In the same fan operation conditions, the results shown for the 7 layers arrays of product in the boxes which the air velocity was 62% lower than the 3 layers arrays and 50.9 % lower than the 5 layers arrays of product. These results were proportional to the bulk area for the air flow.

Flame Spread Over Paper in an Air Stream With a Velocity Change

1984 ◽  
Vol 106 (4) ◽  
pp. 707-712 ◽  
Author(s):  
K. Sato ◽  
K. Miki ◽  
T. Hirano
Keyword(s):  
Flame Spread ◽  
Free Stream ◽  
Ambient Air ◽  
Rate Of Change ◽  
Free Stream Velocity ◽  
Stream Velocity ◽  
Air Velocity ◽  
Velocity Change ◽  
Flame Spreading ◽  
Air Stream

The behavior of downward flame spread over a sheet of filter paper during and after an increase in ambient air velocity was examined. It was shown that the behavior depends not only on the free-stream velocity but also on its rate of change. The extinction mechanisms when the free-stream velocity is instantaneously increased from that for steady flame spread to that above the steady flame spread limit are discussed, and the conditions for continued flame spreading in an air stream with a velocity fluctuation are pointed out.

Generator of Fine Polydisperse Aerosol

2004 ◽  
Vol 69 (7) ◽  
pp. 1453-1463 ◽  
Author(s):  
Pavel Mikuška
Keyword(s):  
Flow Rate ◽  
Geometric Mean ◽  
Air Flow ◽  
Solute Concentration ◽  
Number Concentration ◽  
Solid Particles ◽  
Geometric Standard Deviation ◽  
Air Flow Rate ◽  
Term Operation ◽  
Air Stream

A simple and inexpensive laboratory generator of test aerosol is described. The generator is based on the principle of pneumatic atomization of a solution of a soluble compound by high-velocity air stream. After evaporation of solvent from produced droplets, solid particles are formed. The generator provides continuous unattended long-term operation with constant aerosol output. The performance characteristics of the generator were evaluated by spraying solutions of NaNO3 and (NH4)2SO4. The generator produced polydisperse aerosol in a fine region of particle sizes with a geometric mean diameter of 52.1 nm and a geometric standard deviation of 1.90 for the NaNO3 concentration in the sprayed solution 30 g/l. The total number concentration of the produced aerosol was 3.14 × 107 cm-3 at a nominal air flow rate 78 l/min. The number concentration of particles increased with increasing flow rate of solution, solute concentration and pressure of compressed air through the atomizer or with decreasing total air flow rate through the generator. The change in any of these variables can be used to adjust the particle number concentration. NaNO3 aerosol generation rate was 0.172 mg/min for the NaNO3 concentration in the sprayed solution 30 g/l.

ORIENTATION OF AEDES AEGYPTI IN VERTICAL AIR CURRENTS

1967 ◽  
Vol 99 (3) ◽  
pp. 303-308 ◽  
Author(s):  
P. N. Daykin
Keyword(s):  
Aedes Aegypti ◽  
Air Flow ◽  
Sensory Information ◽  
Vertical Movement ◽  
Stripe Pattern ◽  
Vertical Movements ◽  
Speed Sensor ◽  
Air Stream ◽  
Cybernetic System ◽  
Air Speed

AbstractThe orientation of Aedes aegypti in an upward or downward vertical air current was studied. The vertical movements of A. aegypti which have been activated by CO2 are always against the air flow and toward the inlet end, where the insects alight and probe. With sufficient illumination A. aegypti locate an invisible artificial host whether it is at the top with air moving down or at the bottom with air moving up. They do not attempt to locate a visible, black, artificial host placed downstream. Body attitude is similar in upward or downward air flow. The mosquitoes follow the vertical movement of a surrounding spiral stripe pattern, whether stripe movement is upward or downward, whether air is still or moving vertically with or against the stripes. They will not fly against stripe movement to reach an upstream host, real or artificial. Repellent vapor destroys the upstream orientation when air flow is vertical but not when the flow is horizontal. The stripe-following action is not affected by repellent. The experiments indicate that A. aegypti possesses a vertical-air-speed sensor, of a mechanical type, to direct movement up or down in a vertical air stream. The cybernetic system must be complex and requires cooperative use of mechanical and optical sensory information channels. The initial action of repellent vapor appears to be peripheral rather than central to the nervous system, and to affect only the mechano-, chemo-, and thermo-receptors.

Dynamic Analysis of Airflow in Air-Jet Filling Insertion: Part II — Air Velocity Measurements

2002 ◽  
Author(s):  
Sabit Adanur ◽  
Sayavur I. Bakhtiyarov ◽  
Tacibaht Turel
Keyword(s):  
Dynamic Analysis ◽  
Air Flow ◽  
Flow Characteristics ◽  
Experimental System ◽  
Velocity Measurements ◽  
Air Velocity ◽  
Auburn University ◽  
Air Jet

Air-jet filling insertion is the most popular way of insertion systems in weaving. The heart of the air-jet filling insertion is the air flow, which provides the necessary propelling force for the yarn. In this work, the characteristics of airflow in air-jet filling insertion are discussed. The procedure and experimental system that is developed at Auburn University to measure the air flow characteristics is described.

scholarly journals Experimental Study on the Atomization of Plain Orifice Injector Under Uniform and Non-Uniform Cross Flowing Air Stream

1987 ◽  
Author(s):  
Yan Zhang ◽  
Jun Yong Zhu ◽  
Li Xin Wang ◽  
Ju Shan Chin
Keyword(s):  
Pressure Drop ◽  
Flow Velocity ◽  
Air Flow ◽  
Cross Flow ◽  
Orifice Diameter ◽  
Air Velocity ◽  
Air Stream ◽  
Nozzle Pressure ◽  
Large Orifice ◽  
Air Flow Velocity

The effects of three parameters: air velocity, nozzle pressure drop and injector orifice diameter, on the spray characteristics of a plain orifice injector under uniform and non-uniform cross flowing air stream have been studied experimentally. For uniform cross flowing air stream, the results show that the effects of these parameters are interrelated. The exponents of these terms in a correlation are not constants. Based on a very large amount of experimental data, the following correlation has been derived for Sauter Mean Diameter. SMD = 8.28 • 10 4 V ¯ a A • Δ P ¯ f B • d ¯ C where: A = −1.59 −0.0044ΔP̄f −0.01 d̄ B = −0.13 −0.025 d̄ +0.34 Ma C = 0.36 −0.55 Ma −0.0032ΔP̄f (Va ≤ 140 M/s ; ΔPf ≤ 11 Kg·f/cm2 ; d ≤ 2.5 mm) For small orifice diameters, the drop size distribution parameter, N (Rosin-Rammler distribution ), decreases until a minimum then increases with air velocity. For large orifice diameters, it decreases with air velocity. N always decreases with the increases of nozzle pressure drop or orifice diameter. For non-uniform cross flowing air stream, atomizations under four velocity profiles with same averaged velocity and with a velocity recess of same shape but at different radial positions have been tested. The atomization data were compared with that of uniform cross flowing air stream. Two types of comparison were made based on: a) the undisturbed velocity, b) the averaged velocity, equals to the velocity of uniform cross flowing air stream. For former situation the atomization for non-uniform cross flowing air stream tested is always poorer. The influence from the velocity recess will be maximum at certain nozzle pressure drop. The experimental evidence obtained has shown that cross flow atomization is a combination of pressure atomization (at low air flow velocity) and airblast atomization (at high air flow velocity).

scholarly journals AIR VELOCITY PROFILES IN AIR BLAST FREEZERS FILLED WITH BOXES OF FRUIT PULP MODELS

2004 ◽  
Vol 3 (2) ◽  
Author(s):  
J.V. Resende ◽  
V. Silveira Jr.
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Relative Difference ◽  
Freezing Process ◽  
Fruit Pulp ◽  
Air Flow Rate ◽  
Air Velocity ◽  
Operation Conditions ◽  
Air Stream ◽  
Pass Through

The changes in the air velocities caused by the resistance for the air flow due to fruit pulp model packaged (100 grams) and conditioned in multi layers boxes during freezing process were evaluated and air flow rate were estimated using a method of treatment of the experimental data. The air velocities were measured before the air pass through the pillage of multi layer boxes in the air stream. For the measurements processing was used a non linear regression routine. Air flow rate measured by the present method resulted of the numerical integration of air velocities adjusted profile. Results presented a relative difference 10 % higher than the standard average procedure, which consists in averaging the air velocity measurements performed at each point of the section. In the same fan operation conditions, the results shown for the 7 layers arrays of product in the boxes which the air velocity was 62% lower than the 3 layers arrays and 50.9 % lower than the 5 layers arrays of product. These results were proportional to the bulk area for the air flow.

The Effect of Orifice Plate on Flow Field and Thermal Environment in Oven Box

2015 ◽  
Vol 713-715 ◽  
pp. 47-50
Author(s):  
Hao Li ◽  
Zhi Jun Zou ◽  
Fei Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Thermal Environment ◽  
Air Flow ◽  
Orifice Plate ◽  
Air Velocity ◽  
Change Rate ◽  
Air Volume

Air velocity in oven box is an important factor. The value of air velocity will affect the result of drying. This paper use the method of numerical simulation to research the effect of orifice plate on flow field and thermal environment in oven box. The results show the change rate of thermal environment & air flow field in oven box is depend on supply air volume, and the use of orifice plate will affect the flow field obviously.

scholarly journals AIR STREAM VELOCITY MODELLING IN MULTICHANNEL SPIRAL CYCLONE SEPARATOR

2014 ◽  
Vol 22 (3) ◽  
pp. 183-193 ◽  
Author(s):  
Petras Vaitiekūnas ◽  
Egidijus Petraitis ◽  
Albertas Venslovas ◽  
Aleksandras Chlebnikovas
Keyword(s):  
Turbulent Flow ◽  
Turbulence Model ◽  
Air Flow ◽  
Three Dimensional ◽  
Absolute Error ◽  
Equation System ◽  
Cylindrical Part ◽  
Stream Velocity ◽  
Cyclone Separator ◽  
Air Stream

Numerical modelling problem is investigated in a gas aerodynamics multichannel spiral cyclone separator with a tangential inflow. Experimental and theoretical papers analysing cyclone separator with particularly complex turbulent flow were reviewed. The three-dimensional transport differential equations for incompressible laminar and turbulent flow inside the cyclone separator were presented. They were numerically solved by finite volume method using the Re-Normalisation Group (hereinafter RNG) k-ε turbulence model. The numerical air flow movement was modelled in cyclone separator with the following dimensions: 0.95 m height, 0.330 m diameter, 0.88 m height of spiral-cylindrical part, 0.39 m height of conical part, inflow dimensions (on the side of cylindrical part) according to the drawings were a × b = 28 × 95 mm. The mathematical model of air flow movement in cyclone separator was composed by Navier-Stokes (Reynolds) as the three-dimensional differential equation system. The modelling results were obtained by the tangential and axial velocity profiles in cyclone separator using RNG k-ε turbulence model, the inflow velocity from 4.1 m/s to 15.4 m/s coincided well with the experimental results. This is the first article testing for multichannel cyclone and determined distributions of aerodynamic parameters. The absolute error between experimental and modelling results changed from 0.01 to 0.24 units.

The Analysis of Intake Manifold Air Stream Velocity on Different Material Roughness

2014 ◽  
Vol 661 ◽  
pp. 143-147
Author(s):  
Muhammad Arif Abdul Hamid Pahmi ◽  
Sharzali Che Mat ◽  
Ahmad Nazri Nasruddin ◽  
Mohd Fauzi Ismail ◽  
Mohd Najib Yusof
Keyword(s):  
Surface Roughness ◽  
Cast Iron ◽  
Air Flow ◽  
Three Dimensional ◽  
Internal Surface ◽  
Intake Manifold ◽  
Stream Velocity ◽  
Air Stream ◽  
Air Flow Velocity ◽  
Primary Materials

Intake manifold is a crucial part in an engine that acts as a medium for air flow to mix with the fuel before entering the combustion chamber. For years, cast iron and aluminium were the primary materials chosen for fabrication of an intake manifold before plastic based material was introduced to the field. However, there is lack of research involving the usage of plastic as the intake manifold material. In this paper, the effects of internal surface roughness variations (Cast iron, aluminium and plastic) inside the intake manifold were studied. Three dimensional, intake manifold model was developed to simulate the airflow. The study emphasized on the airflow velocity inside the intake manifold. The study showed that the surface roughness influenced the air flow velocity near the intake manifold outlet. The plastic based intake manifold exhibited the highest air stream velocity (near the intake manifold outlet) at 477.770 m/s. This value is 0.60% and 0.40% higher than those produced by the cast iron and aluminium intake manifold, respectively.

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