scholarly journals Numerical and experimental study of the influence of nozzle flow parameters on yarn production by jet-ring spinning

2018 ◽  
Vol 57 (4) ◽  
pp. 2975-2989
Author(s):  
Hassan A.H. Ahmed ◽  
Rola S. Afify ◽  
Ahmed H. Hassanin ◽  
Ibrahim A. El-Hawary ◽  
Raafat I. Mashaly
2015 ◽  
Vol 92 ◽  
pp. 02105
Author(s):  
Ondřej Veselý ◽  
Ludmila Nováková ◽  
Josef Adamec

Author(s):  
Walter E. Bruce ◽  
Melissa B. Carter ◽  
Alaa A. Elmiligui ◽  
Courtney S. Winski ◽  
Sudheer Nayani ◽  
...  

2021 ◽  
Vol 2119 (1) ◽  
pp. 012029
Author(s):  
M V Philippov ◽  
I A Chokhar ◽  
V V Terekhov ◽  
V I Terekhov

Abstract Local and integral characteristics of heat transfer are obtained at varying the Reynolds number Re = 5500, 11000, the distance between the jets y/D = 1.8, and the distance from the jets to the surface z/D = 0.5-10 for the system of two identical impinging jets. It is found in experiments that the effect of an adjacent jet leads to enhancement of local heat transfer at large distances between the nozzles and the barrier. It is also shown that an increase in the Re number increases integral heat transfer, and, at the same time, weakens the inter-jet interaction. The paper analyzes the scenarios of the behavior of local and integral heat transfer depending on the geometric and flow parameters of the system of two circular turbulent jets.


2020 ◽  
Vol 4 (394) ◽  
pp. 121-128
Author(s):  
Nikolay N. Ponomarev

Object and purpose of research. The object of this work is gas turbine outlet consisting of axial-radial diffuser with the struts and the volute. The purpose is to create a methodology for engineering calculations, taking into account the mutual influence of the diffuser and the volute. Materials and methods. Experimental study of the flow in the models of outlets by measuring total and static pressure in characteristic sections. Calculation of integral and averaged flow parameters in measurement sections. Visualization of boundary flows. Based on the experimental results, development of regression models for the correction factors to be applied in the theoretical model, with selection of relevant factors. Main results. An experimental study of 23 variants of models with a total volume of 112 experimental points (modes) was carried out. On the basis of the experiment, methodology and program for engineering calculation of total pressure losses in the outlets were developed. It was found that the installation of guide blades and radial ribs in the diffuser in order to reduce local expansion angles with the ultimate purpose of mitigating total pressure losses actually does not lead to this result due to the because the flow in the diffuser becomes asymmetric due to its interaction with the volute. Visualization of boundary flows in the diffusers and the volutes has been performed, which makes it possible to identify the locations of separations causing increased pressure losses. Conclusion. An engineering method for calculating the total pressure loss in gas turbine outlet has been developed. The technique makes it possible, taking size restrictions into account, to select the geometry of the flow section that ensures minimum total pressure loss.


Author(s):  
Fernando S. Rocha ◽  
Thiago G. Costa ◽  
Ailton G. Oliveira ◽  
Thiago A. Costa ◽  
Ivaldo L. Ferreira ◽  
...  

2013 ◽  
Vol 739 ◽  
pp. 338-362 ◽  
Author(s):  
R. Ledesma-Alonso ◽  
J. E. V. Guzmán ◽  
R. Zenit

AbstractAn experimental investigation was conducted to study the dynamical behaviour of a model valve in a pulsatile flow. The valve is modelled as a pair of curved, rectangular, flexible leaflets that open and close under a time-periodic flow. Using image analysis, the range of flow parameters for which a valve (of a particular geometry and material properties of the leaflets) works correctly were identified. A correct performance was considered to be when the valve opened in one direction but blocked the flow in the reversed direction. A model is proposed to predict the performance of the valves. Furthermore, an analysis of fluid strains is conducted for valves that operate correctly to identify the influence of the valve’s design on fluid stresses. The main purpose of this investigation is to gain insight for the design of future prosthetic heart valves.


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