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CFD model of mixture gas flow in the vacuum column 12T-70102, existing state of internals
Říha, Zdeněk
The report contains description of fluid flow for case with existing state of the column 12T -70102. Vapor flow was mainly calculated in the above mentioned geometry. In last iteration the liquid droplet (diameter 0,3mm) were injected into the geometry through the nozzle 12, see enclosure in the report. Introductory section of the enclosuere contains pictures with geometry and boundary conditions description, See figure G1. Then, slice plan follows, see figure G2. Next pictures show distribution of pressure and velocity on given slices. Pictures at the end of the enclosure show path-lines distribution and droplets particle traces distribution in the solved geometry.
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CFD model of mixture gas flow in the vacuum column D-6501
Říha, Zdeněk
The report contains CFD results and description of the gas mixture flow in the vacuum column D-6501. Two rotationally opposite (swirl) input nozzles S1 and S2 (ID 0,835m) create main input of vapour into the vacuum column. There are two enhanced vapour horn (EVH) distributor, for given input nozzle (S1, S2) separately. Enhanced vapour horn makes redistribution of vapour leaded from above mentioned nozzles. There also is next input of vapor given by bottom striping section. The inner diameter of the column is 7,464m and solved domain has height c. 15m. Aim of the calculation is to show distribution of calculated variables (velocity, pressure, density, etc.) on given slices. Mainly, we would like to know if the distribution of velocity is sufficiently uniform at the input into the packing bed SECTION “B”.
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CFD model of mixture gas flow in the vacuum column D-6501, adjusted EVH and tray
Říha, Zdeněk
The report contains CFD results and description of the gas mixture flow in the vacuum column D-6501 with adjusted internals against last calculated case, see [1]. Two rotationally opposite (swirl) input nozzles S1 and S2 (ID 0,835m) create main input of vapour into the vacuum column. There are two enhanced vapour horn (EVH) distributor, for given input nozzle (S1, S2) separately. Enhanced vapour horn makes redistribution of vapour leaded from above mentioned nozzles. There also is next input of vapor given by bottom striping section. The inner diameter of the column is 7,464m and solved domain has height c. 15m. Aim of the calculation is to show distribution of calculated variables (velocity, pressure, density, etc.) on given slices. Mainly, we would like to know if the distribution of velocity is sufficiently uniform at the input into the packing bed SECTION “B”
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CFD model of multiphase flow in the abrasive water jet tool
Říha, Zdeněk
The possibility of using CFD fluid flow modeling in area of tools with abrasive water jet is described in the paper. The correct function of such tool is based on proper setting of multiphase flow of water, air and solid particles in the inner space of the tool. The multiphase fluid flow numerical simulation can provide information which show relation between the geometry and the flow field. Then, this stable CFD model of multiphase flow creates key to design of the tool able to work with higher efficiency.
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The flow of mixture vapors in the athmospheric column, comparison of new distributor and new tray
Říha, Zdeněk
The description of CFD analysis and the description of mixture gas flow in the atmospheric column are listed in the report. This article builds on previous work [1]. There were calculated two cases with original distributor and with GT-OPTIFLOW distributor, see [1]. This article adds next two cases. The case with adjusted GT-OPTIFLOW distributor (enclosure 1) and adjusted GT-OPTIFLOW distributor with newly designed the chimney tray and new layout of the packing bed (enclosure 2). The flow area of the newly designed chimney tray is smaller than for previous design (5,36m2 vs. 6,89m2). New layout of the packing bed has smaller flow area (28,27m2 vs. 29,35m2) and higher pressure drop (129 Pa vs. 80Pa) in comparison with last design of the packing bed also used in [1].
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Předpověď proudění v trysce
Říha, Zdeněk
V článku je uveden popis řešení proudění tekutiny v trysce pomocí software ANSYS-Fluent. V daném prostoru dochází k samobuzenému kmitání hydraulických veličin. Tlak na vstupu do trysky se pohybuje kolem 10-ti MPa (abs.). Je tedy zřejmé, že se jedná o fyzikálně velmi složité vícefázové proudění. Vysoký tlak na vstupu způsobueí vznik vysokých rychlostí v trysce a na výstupu z ní. Hydraulické podmínky v řešené soustavě si potom vynucují zahrnout do již tak komplikovaného výpočtu stlačitelnost zúčastněných fází. Cílem výpočtů je zjistit, k čemu vlastně dochází uvnitř samotné trysky v případě, že na výstupu z trysky dochází k pulznímu výtoku paprsku tekutiny.
Plný tet: UGN_0426588 -  PDF
Plný text: content.csg - PDF
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CFD code as a helper for the design of the water jet cutting device
Říha, Zdeněk
The efficiency of the amplification of high pressure pulsations in the geometric transition between larger and smaller pipes is analysed in this paper. Three types of geometric transitions are compared in the paper: step change, conical and radius change of pipe diameters. In other words, water flow in a device for water jet cleaning and cutting is evaluated. There are ultrasonic pulsations of high pressure in the given domain.
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Ultrasonic pulsations of pressure in a tool for water jet cutting
Říha, Zdeněk ; Foldyna, Josef
Water flow in a tool for water jet cleaning and cutting is evaluated in this paper. There are ultrasonic pulsations of high pressure in the given domain. The efficiency of the amplification of high pressure pulsations in the transitional space between larger and smaller pipes is analysed. Three types of transitional spaces are compared in the paper: step change, conical and radius change of pipe diameters.
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Forces and Moments in CFD Analysis
Říha, Zdeněk ; Foldyna, Josef
The paper shows how to find the force point of action, when we know the total force and the total moment. It is usual case if we solve fluid flow with help of a CFD code. Correct interpretation of force´s act is very important for next possible analysis.
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