EXPERIMENTAL SUBSTANTIATION OF PARAMETERS OF TWO-PHASE «AIR – GRAIN» FLOW REQUIRED TO SIMULATE OPERATION OF THE PNEUMATIC SYSTEM OF THE GRAIN-CLEANING MACHINE

Due to the cold and dry climate during the winter season of Central Asia, in order to prevent frostbite and vines drying out for wine grapes, the common methods are burying the vines in winter under a thick layer of soil and then cleaning them out in the next spring. The design of existing vine digging machinery is not precise enough and can only remove the outer layer of the soil on both sides and the top. It cannot clean the soil from the central area of the buried vine. Sometimes, the branches and buds get damaged due to uneven driving condition. To solve the problem, an innovative non-contact blower was designed and tested to clean the vine. In this paper, the design specifications and operation parameters of the blower were determined according to the agronomic properties of the grapevines. Fluent-EDEM coupling, that is, with the help of Engineering discrete element method (EDEM) and CFD fluid simulation software Fluent, was the most common method for dynamic simulation of gas-solid two-phase flow. The Fluent-EDEM coupling simulation was used to simulate the dynamics of soil particles under the action of different wind speeds and blowing patterns, with the goal of a high soil cleaning rate. A prototype of the soil cleaning blower was manufactured and tested at the vineyards of Ningxia Yuquanying Farm in China. The results showed that the blower had an operation efficiency of 4669 m2·h−1, with an average soil removal rate of 80%. The efficiency of covering soil cleaning and rattan raising was greatly improved, and the damage rate of the vines, branches and the buds was greatly reduced.

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Analysis of a pneumatic system for a two-phase flow sugar

The International Journal of Multiphysics ◽

10.1260/1750-9548.7.4.325 ◽

2013 ◽

Vol 7 (4) ◽

pp. 325-338

Author(s):

Gustavo Otero R. ◽

Geanette Polanco ◽

Miguel Asuaje

Keyword(s):

Two Phase Flow ◽

Pneumatic System ◽

Phase Flow ◽

Two Phase

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Condensation inside smooth horizontal tubes: Part 2. Improvement of heat exchange prediction

Thermal Science ◽

10.2298/tsci140815045r ◽

2017 ◽

Vol 21 (3) ◽

pp. 1479-1489 ◽

Cited By ~ 4

Author(s):

Volodymyr Rifert ◽

Volodymyr Sereda ◽

Peter Barabash ◽

Vadim Gorin

Keyword(s):

Close Agreement ◽

Precise Definition ◽

Film Condensation ◽

Flow Conditions ◽

Two Phase ◽

Pressure Losses ◽

Horizontal Tubes ◽

Definition Of ◽

The Heat Transfer Coefficient ◽

Experimental Substantiation

In this study, a theoretical model of film condensation inside horizontal tubes with more precise definition of friction coefficient on interphase is presented to calculate the heat transfer coefficient under two-phase annular and intermediate flow conditions. This more precise definition contains experimental substantiation of correction for calculation of pressure losses by friction and correction that takes into account surface suction on the interphase. Comparison of this model with the experimental data of various authors demonstrates that the results are in satisfactory and close agreement.

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Analysis and features of operation of fractional grain cleaners and secondary seed cleaning separators

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/845/1/012064 ◽

2021 ◽

Vol 845 (1) ◽

pp. 012064

Author(s):

VI Orobinsky ◽

A M Gievsky ◽

I V Baskakov ◽

V A Gulevsky ◽

A V Chernyshov

Keyword(s):

Experimental Studies ◽

Aerodynamic Characteristics ◽

Agricultural Science ◽

Pneumatic System ◽

Fractionation Process ◽

Post Harvest ◽

Agricultural Engineering ◽

Grain Processing ◽

Cleaning Equipment ◽

Cleaning Machine

Abstract To obtain high-quality grain and seeds, it is necessary to clean the combine heap of weeds. Modern air-screen grain cleaners equipped with a screen cleaning systems, flat screens and a double-aspiration pneumatic system with pre-screen and post-screen cleaning channels are used. The fractional principle of post-harvest grain processing is promising. To create a universal grain cleaning machine to isolate the main fraction from the grain heap at the first stage of post-harvest processing, Voronezh State Agar University named after Emperor Peter I carried out theoretical and experimental studies, which made it possible to develop OZF-50, OZF-80 and SVS-30 separators. The machines have higher productivity, the original sieve design with an increased share of sorting sieves and an exclusive aspiration system. A number of new technical solutions have been used in the design of the separators, protected by patents of the Russian Federation. Theoretical prerequisites established the possibility of increasing the productivity 1.6-1.8 times according to GOST R 52325-2005. The total air consumption of the pneumatic system of grain cleaning machines can be reduced by 25-40%. Further improvement of separators requires a deeper study of the grain fractionation process, aerodynamic characteristics of aspiration systems, receiving and distribution devices, and establishment of close mutually beneficial relations between scientific institutions and agricultural engineering enterprises. This can contribute to the development of both domestic agricultural science and grain cleaning equipment production.

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Effect of Shock Loading on the Microstructure of Uniloy 326

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052535 ◽

1974 ◽

Vol 32 ◽

pp. 504-505

Author(s):

K. P. Staudhammer ◽

L. E. Murr

Keyword(s):

Grain Size ◽

Shock Loading ◽

Current Investigation ◽

Two Phase ◽

05 C ◽

Shock Deformation ◽

Heat Treated

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.

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Exsolution and inversion in pigeonite from the Whin Sill, Northern England

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109513 ◽

1978 ◽

Vol 36 (1) ◽

pp. 474-475

Author(s):

P.P.K. Smith

Keyword(s):

High Temperature ◽

Low Temperature ◽

Homogeneous Nucleation ◽

Silicate Mineral ◽

Antiphase Boundaries ◽

Two Phase ◽

Primitive Form ◽

The Core ◽

Nucleation Mechanisms ◽

And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

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Shock consolidation of Ni-Ti alloy powder

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143730 ◽

1986 ◽

Vol 44 ◽

pp. 430-431

Author(s):

Naresh N. Thadhani ◽

Thad Vreeland ◽

Thomas J. Ahrens

Keyword(s):

Alloy Powder ◽

Amorphous Material ◽

Ti Alloy ◽

Two Phase ◽

Near Surface ◽

Optical Micrograph ◽

Shock Compaction ◽

Powder Particles ◽

Ti Powder ◽

Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

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A Comparison of Tem and Apfim to the Interpretation of Modulated Microstructures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011742x ◽

1985 ◽

Vol 43 ◽

pp. 70-71

Author(s):

M.G. Burke ◽

M.K. Miller

Keyword(s):

Low Temperature ◽

Microstructural Characterization ◽

Superlattice Reflection ◽

High Volume ◽

Atom Probe ◽

Dark Field ◽

Miscibility Gap ◽

Second Phase ◽

Two Phase ◽

Probe Field

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.

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A TEM study of the influence of microstructure on the superplastic behavior of a U-5.8 wt.% Nb alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144310 ◽

1986 ◽

Vol 44 ◽

pp. 568-569

Author(s):

G. Mackiewicz Ludtka

Keyword(s):

Grain Size ◽

Heating Rate ◽

Phase Field ◽

Single Phase ◽

Superplastic Behavior ◽

Two Phase ◽

Single Phase Field

Historically, metals exhibit superplasticity only while forming in a two-phase field because a two-phase microstructure helps ensure a fine, stable grain size. In the U-5.8 Nb alloy, superplastici ty exists for up to 2 h in the single phase field (γ1) at 670°C. This is above the equilibrium monotectoid temperature of 647°C. Utilizing dilatometry, the superplastic (SP) U-5.8 Nb alloy requires superheating to 658°C to initiate the α+γ2 → γ1 transformation at a heating rate of 1.5°C/s. Hence, the U-5.8 Nb alloy exhibits an anomolous superplastic behavior.

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