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Numerical Simulation of Flow Field in Air-Jet Loom Main Nozzle

References [1] Adanur, S., Mohamed, M. H. (1991). Analysis of airflow in air-jet filling insertion. Textile Research Journal, 61(5), 253-258. [2] Yan, Y., Zhang, W., Chen, Y. (1995). Intermittence of air-jet influence on air-jet weft insertion. Journal of China Textile University, 21(4), 96-100. [3] Mohamed, M. H., Salama, M. (1986). Mechanics of a single nozzle air-jet filling insertion system part I: nozzle design and performance. Textile Research Journal, 56(11), 683-690. [4] Zhu, Z. (1994). Weft features of airflow from main nozzle (in

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The Investigation of the Cavitation Phenomenon in the Laval Nozzle with Full and Partial Surface Wetting

- Technical University of Ostrava, Mechanical Series, 2011 (57), No. 1, 267 -274. [13] B. Frodlová, P. Rudolf, L. Zavadil, M. Kozubková, J. Rautová, Effect of Partial Wettability on the Flow and Cavitation Area in the Laval Nozzle. Transactions of ANSYS 2011 Conference, 2011, 1 - 8. (in Czech) [14] Leighton, T.: The Acoustic Bubble. Physics In Medicine And Biology. Academic Press: 1997, p. 613. ISBN: 978-0-12-441921-6 [15] Cheremisinoff N. P.: Noise Control in Industry. William Andrew: 1996. 203 p. ISBN: 978

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Plastic limit load of ellipsoidal pressure vessel head with nozzle under internal pressure loading

), Brussels. Gerdeen J.C. (1979): A critical evaluation of plastic behavior data and a unified definition of plastic loads for pressure components. - Welding Research Council Bulletin, No.254, pp.1-64. Hsieh M.F., Moffat D.G. and Mistry J. (2000): Nozzles in the knuckle region of a torispherical head: limit load interaction under combined pressure and piping loads. - Int. J. Pressure Vessels and Piping, vol.77, No.13, pp.807-815. Hsieh M.F., Moreton D.N., Mistry J. and Moffat D.G. (2002): Limit loads for knuckle

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Cooled Turbine Cantilevered Nozzle Mounting and Sealing System

Abstract

Small advanced turboprop and turboshaft engines, with two-stage high-pressure turbine (HPT), need to meet several challenges. Described herein is an exemplary solution adopted for a cantilevered HPT nozzle mounting and sealing system that helped to meet requirements for size constraint and sealing of split lines and mounting features. Since clearances do not scale down with engine size due to manufacturing tolerances, there is a very limited space available between first and second stage rotors to secure HPT nozzle and to provide means of cooling air supply. Due to small diameters, cavities and size of the parts and assembly access becomes very difficult and precluded the use of typical solutions – like supply air spooilers – known from bigger engines. Relatively larger clearances require also efficient solution for sealing leakage, which was achieved by means of high-temperature braided “rope seals”. The nozzle segments have weight effective hook-type outer band mounting to HPT outer casing and are axially retained by HPT shroud with a snap ring. The hook cavities were used as pockets for rope seals that are subsequently compressed during assembly making it more difficult. However, by special design of the pockets and parts engagement sequence, the assembly process was optimized even though it is so called blind assembly. The sealing system function is not only reducing leakages that are detrimental to a turbine efficiency, but also allow for pressurizing the cavity between the nozzle outer band and HPT outer casing with cooling air thus preventing from hot gas ingestion by higher back-flow margin (BFM) resulting in higher durability of the turbine.

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Determination of the Crack Resistance Parameters at Equipment Nozzle Zones Under the Seismic Loads Via Finite Element Method

Abstract

The present paper is devoted to the problem of the assessment of probable crack growth at pressure vessel nozzles zone under the cyclic seismic loads. The approaches to creating distributed pipeline systems, connected to equipment are being proposed. The possibility of using in common different finite element program packages for accurate estimation of the strength of bonded pipelines and pressure vessels systems is shown and justified. The authors propose checking the danger of defects in nozzle domain, evaluate the residual life of the system, basing on the developed approach.

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Mathematical Investigation of the Cavitation Phenomenon in the Nozzle with Partially Surface Wetting

Abstract

Partially surface wetting has a great influence on friction losses in the fluid flow in both the pipeline system and the complex shape of hydraulic elements. In many hydraulic elements (valves, pump impellers), cavitation is generated, which significantly changes the hydraulic flow parameters, so the last part of the article is devoted to the mathematical solution of this phenomena and evaluates the impact of wall wetting on the size and shape of the cavitation area which appears in the nozzle and in small gaps at special conditions. If the cavitation appears e. g. near the wall of pipes, the blades of turbine or a pump, then it destroys the material surface. On the basis of this physical experiment (nozzle), a two-dimensional (2D) mathematical cavitation model of Schnerr-Sauer was made and calculated shape and size of the cavitation region was compared with the experiment. Later this verified model of cavitation was used for cavitation research flow with partial surface wetting. The pressure drop and the size of the cavitation area as it flows from partially surface wetting theory was tested depending on the adhesion coefficient.

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Some Approach to Upper Layer Cooling Process with Spray Stream Generated by Water Nozzle Using Computer Simulation Method

Abstract

Computer model of upper layer cooling applying spray streams generated by water nozzle was presented in the paper. Assumptions, mathematical model and input data were given. Simulation process for assumed fire scenario and different droplet diameters was described. Results of the simulation and their analysis were presented. General conclusions and final remarks were included at the end of this work.

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Evaluation of Flat Fan Nozzles Operating Parameters Under Conditions of Accelerated Boundary and Destructive Wear

References ASAE S471 (1999). Procedure for measuring sprayer nozzle wear rate. St. Joseph, Mich.: ASAE Standards, 46th ed. Directive 2009/128/EC (2009). Establishing a framework for Community action to achieve the sustainable use of pesticides. Official Journal of the European Union L309, 71-86. Duvnjak, V., Pliestić, S., Filipović, D., Banaj, Đ., Andrić, L. (2009). Effect of orifice wear of boom sprayer nozzles on spray characteristic. Agronomski glasnik , 71 (4), 261-270. EN 13790-1:2003 (2003). European Standard. Agricultural

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Comparing Nozzles with Different Wear Rate and Working with the Same Application Rate of Different Plant Protection Products in Aspect of Plants Condition

References Agüera, F., Nuyttens, D., Carvajal, F. and Sánchez-Hermosilla, J. (2012) Fractal analysis of agricultural nozzles spray. Scientia Agricola , 69(1), 6-12. Berry, P.M., Sterling, M., Spink, J.H., Baker, C.J., Sylvester-Bradley, R., Mooney, S.J., Tams, A.R. and Ennos, A.R., (2004). Understanding and reducing lodging in cereals. Advances in Agronomy , 84 , pp.217-271. Braekman, P., Foque, D., Messens, W., Van Labeke, M.C., Pieters, J.G. and Nuyttens, D. (2010). Effect of spray application technique on spray deposition in greenhouse

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Researches on the reliability of spraying machines in vineyards and orchards

Abstract

The goal of the research was to determine the level of abrasion of different types of nozzles during different types of uses and at different pressure values.

The experiment assembly consists of an ATOM-300 carried sprayer, manufactured by S.C. TEHNOFAVORIT S.A. Bonţida-Cluj, and a stand for testing the distribution uniformity of the vineyard and orchard sprayers Herbst ED20-900, manufactured by Ernst Herbst Prüftechnik e. K. Hirschbach-Germany.

The 4 types of nozzles used were Lechler Ceramic 1.0 and 1.2; Lechler TR 80-30 and Lechler ITR 80-015 with air induction.

The measurements were made on a water pressure of 10 bar and 20 bar, and the testing period was equivalent with the duration of a campaign. The study below presents the variations of the debit measured in each type of nozzle according to the time and pressure.

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