Study on the Inaccuracies of Air Velocity Measured by Pitots with Different Outer Diameter in a Air Duct

2011 ◽  
Author(s):  
Wu Hubiao ◽  
Zou Zhijun ◽  
Huang Chen ◽  
Wang Fei ◽  
Li Hao ◽  
...  
Keyword(s):  
Outer Diameter ◽  
Air Velocity

An analysis of the problem of lodging with particular reference to wheat and barley

1975 ◽  
Vol 85 (3) ◽  
pp. 495-507 ◽  
Author(s):  
M. Neenan ◽  
J. L. Spencer-Smith
Keyword(s):  
Young’S Modulus ◽  
Theoretical Study ◽  
Young's Modulus ◽  
Lateral Force ◽  
Outer Diameter ◽  
Structural Failure ◽  
Air Velocity ◽  
Wind Tunnel Experiments ◽  
Two Factors ◽  
The Relationship

SUMMARYIt has been shown that structural failure in small grain cereals occurs by buckling rather than by loss of anchorage. A theoretical study established the relationship between a lateral force applied to the head, and failure of the straw. Resistance to bending is determined by two factors, Young's modulus and outer diameter of the straw. These were determined in laboratory tests. The value of Young's modulus was affected by stage of maturity of the straw. Wind-tunnel experiments established a relationship between air velocity and deflexion of the head. An attempt was made to calculate the wind speed necessary to cause straw breakage in the field. The kinetic effect of raindrops was not a significant factor in lodging. Attention has been drawn to the possible importance of taper in the straw.

scholarly journals Reduction of dynamic error in measurements of transient fluid temperature

2011 ◽  
Vol 32 (4) ◽  
pp. 55-66 ◽  
Author(s):  
Magdalena Jaremkiewicz
Keyword(s):  
Time Constant ◽  
Dynamic Error ◽  
Fluid Velocity ◽  
Time Lag ◽  
Outer Diameter ◽  
Fluid Temperature ◽  
Air Velocity ◽  
Start Up ◽  
Different Diameters ◽  
High Degree

Reduction of dynamic error in measurements of transient fluid temperatureUnder steady-state conditions when fluid temperature is constant, temperature measurement can be accomplished with high degree of accuracy owing to the absence of damping and time lag. However, when fluid temperature varies rapidly, for example, during start-up, appreciable differences occur between the actual and measured fluid temperature. These differences occur because it takes time for heat to transfer through the heavy thermometer pocket to the thermocouple. In this paper, a method for determinig transient fluid temperature based on the first-order thermometer model is presented. Fluid temperature is determined using a thermometer, which is suddenly immersed into boiling water. Next, the time constant is defined as a function of fluid velocity for four sheated thermocouples with different diameters. To demonstrate the applicability of the presented method to actual data where air velocity varies, the temperature of air is estimated based on measurements carried out by three thermocouples with different outer diameters. Lastly, the time constant is presented as a function of fluid velocity and outer diameter of thermocouple.

Structure of rattlesnake venom lectin determined by single particle high-resolution electron microscopy

1996 ◽  
Vol 54 ◽  
pp. 62-63
Author(s):  
Peter D. Moisiuk ◽  
Daniel R. Beniac ◽  
Ross A. Ridsdale ◽  
Martin Young ◽  
Bhushan Nagar ◽  
...  
Keyword(s):  
High Resolution Electron Microscopy ◽  
Lipid Monolayer ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
Single Particles ◽  
Crotalus Atrox ◽  
3D Reconstructions ◽  
X Ray ◽  
Rattlesnake Venom ◽  
Covalently Linked

Venom from the rattlesnake Crotalus atrox contains a mixture of enzymes that induce a localized effect leading to hemorrhaging, necrosis and edema. As a member of the crotalid family of snake venoms, Crotalus atrox venom contains a C-type lectin that will agglutinate blood cells in a Ca2+-dependent fashion. The lectin is a hydrophilic protein, consisting of two covalently linked, 135 amino acid residues, identical subunits that are rich in aspartic acid, glutamic acid and lysine. Sequence homology with known carbohydrate recognition domains (CRDs) indicates that rattlesnake venom lectin (RSLV) contains a CRD motif that is not linked to accessory domains. Preliminary X-ray diffraction and sedimentation analysis has indicated that lectin from Crotalus atrox forms decamers composed of two five-fold symmetric pentamers. Single particles of RSVL imaged at – 171°C displayed two distinct orientations on the specimen support (Figure a) following incubation in a crystallization Teflon well, coated with a lipid monolayer consisting of phosphatidylcholine and monosialoganglioside. When lying in an end-on orientation, the lectin exhibited a “pentagonal ring” with an outer diameter of 6.7 nm and an inner hollow core of 1.7 nm. A side orientation was also seen, whereby a thickness of 5.8 nm was measured for the lectin. Image processing of 2280 single particles placed in 100 classes (Figure b) led to 3D reconstructions of RSVL (Figure c). Density limited 3D reconstructions showed the lectin to be made of two five-fold symmetrical rings covalently linked between the five subunits that constitute each ring of this homodimer. These results are consistent with sedimentation and preliminary X-ray diffraction analysis on the shape of RSVL and provide the framework for structural verification by 2D electron crystallography.

Analysis of LPG diffusion flame in tube type burner

2019 ◽  
Vol 13 (3) ◽  
pp. 5278-5293
Author(s):  
Vipul Patel ◽  
Rupesh Shah
Keyword(s):  
Diffusion Flame ◽  
Emission Characteristic ◽  
Flame Stability ◽  
Liquefied Petroleum Gas ◽  
Air Velocity ◽  
Length Fraction ◽  
Low Emission ◽  
Tube Type ◽  
Stability Limits ◽  
Co Emission

The present research aims to analyse diffusion flame in a tube type burner with Liquefied petroleum gas (LPG) as a fuel. An experimental investigation is performed to study flame appearance, flame stability, Soot free length fraction (SFLF) and CO emission of LPG diffusion flame. Effects of varying air and fuel velocities are analysed to understand the physical process involved in combustion. SFLF is measured to estimate the reduction of soot. Stability limits of the diffusion flame are characterized by the blowoff velocity. Emission characteristic in terms of CO level is measured at different equivalence ratios. Experimental results show that the air and fuel velocity strongly influences the appearance of LPG diffusion flame. At a constant fuel velocity, blue zone increases and the luminous zone decreases with the increase in air velocity. It is observed that the SFLF increases with increasing air velocity at a constant fuel velocity. It is observed that the blowoff velocity of the diffusion flame increases as fuel velocity increases. Comparison of emission for flame with and without swirl indicates that swirl results in low emission of CO and higher flame stability. Swirler with 45° vanes achieved the lowest CO emission of 30 ppm at Φ = 1.3.

Transient Models to Analyze the Influence of the Air Velocity and Ducts Diameter on the Performance of Earth-Air Heat Exchangers

2016 ◽  
Vol 43 (5-6) ◽  
pp. 503-520 ◽  
Author(s):  
R. S. Brum ◽  
J. V. A. Ramalho ◽  
Luiz Alberto O. Rocha ◽  
L. A. Isoldi ◽  
E. D. dos Santos
Keyword(s):  
Heat Exchangers ◽  
Air Velocity ◽  
Transient Models

Improvement Of Free Convection From Three horizontal Finned Cylinders Fixed Between Two Walls

2018 ◽  
Vol 6 (2) ◽  
pp. 98-114 ◽  
Author(s):  
Hassan K. Abdullah ◽  
Haneen H. Rahman
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Prandtl Number ◽  
Convection Heat Transfer ◽  
Constant Heat Flux ◽  
Heat Fluxes ◽  
Head Orientation ◽  
Outer Diameter ◽  
Gravitational Acceleration ◽  
Convection Heat

Improvement of  free convection heat transfer from three finned cylinders arranged at a triangle shape fixed between two walls has been investigated in this study. Three mild steel finned cylinders fixed between two walls from Pyrex glass have been used as a test rig. It has been changed the spacing between the cylinders (X/D=1,2,3 & S/D=2,4,6) and the head orientation of a triangle to the top under constant heat flux values (38, 254, 660, 1268) W/m2 and compare with case of three finned cylinders arranged in vertical array in line fixed between two wall. The experiments are carried for Rayleigh number (Ra) from (15x103 to 14 x104 ) and Prandtl  number from (0.706-0.714 ). The results indicated an increase in Nu with increasing Ra for all cylinders. Furthermore,hx and Nu increased proportionally with the increasing of cylinder spacings for all heat fluxes. Also the experimental results show the case of triangle arrangement is improvement the heat transfer more than case of vertical arrangement. Heat transfer dimensionless correlating equation is also proposed.              Nomeclature: Ax: surface area(m2), T∞: surrounding temperature(k), D: the outer diameter of fin (m), Kf: the thermal conductivity for air at film temperature(W/m.k), hx: Local convection heat transfer(W/m2.k),  Gravitational acceleration(m/s2), I: Electric current (Amp), Nu: Nusselt number, Pr: Prandtl number

Karakteristik aliran dua fase pada saluran ekspansi tiba-tiba

2018 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Latif Ngudi Wibawanto ◽  
Budi Santoso ◽  
Wibawa Endra Juwana
Keyword(s):  
Standard Deviation ◽  
Flow Pattern ◽  
Flow Characteristic ◽  
Homogeneous Model ◽  
Flow Equation ◽  
Pressure Recovery ◽  
Sudden Expansion ◽  
Air Velocity ◽  
Model Flow ◽  
Two Phases

This research was conducted to find out the flow characteristic of two phases through the channel with sudden expansion in the form of change of flow pattern and pressure recovery. The test was carried out with variation of superficial velocity of water 0.2-1.3 m / s and superficial air velocity of 0.2-1.9 m / s resulting in pattern of three flow patterns ie bubble, plug, and slug. The expansion channel resulted in some changes to the flow pattern that originally plugs in the upstream channel into bubble in the downstream channel and the slug becomes plug. Pressure recovery experimental results compared with the homogeneous model flow equation and Wadle correlation, both correlations have predictions with standard deviation values of 0.32 and 0.43.

Study of effect of deforming element acting surfaces angle on characteristics of power dynamics of combined hole mandrelling method

2020 ◽  
pp. 212-216
Author(s):  
A.V. Shchedrin ◽  
V.F. Aleshin ◽  
I.Yu. Ignatkin ◽  
N.Yu. Chikhacheva
Keyword(s):  
Power Dynamics ◽  
Outer Diameter ◽  
Force Dynamics ◽  
Steel 12Khn3a

The effect of the deforming element acting surfaces angle on the characteristics of the force dynamics of the combined deforming cutting mandrelling method of holes in the workpieces of various height and outer diameter from steel 12KhN3A is studied.

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