Optimisation Analysis of Structural Parameters of an Annular Slot Ejector Based on the Coanda Effect

Feng-liang, WU; Li, Zhisheng

doi:10.1155/2020/8951353

Cited by 3 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, as can be seen from Figure 12, these 2 types of ejectors have opposite characteristics. In particular, the Venturi ejector (Liu 2014;Xu et al 2016Xu et al , 2020Liu et al 2016;Hill et al 1990Hill et al , 1992Samad et al 2012;Olaru 2020), provides maximum vacuum at minimum consumption, while the Coanda ejector (Wu, Li 2020;Xie 1993;Fleischer et al 2013;Lien, Davis 2008;Natarajan, Onubogu 2012;Natarajan et al 2018;Dumitrache et al 2011;Sierra et al 2017;Cîrciu, Dinea 2010;Cîrciu, Rotaru 2019), provides average values of vacuum at high consumption. Therefore, Venturi ejectors are used with vacuum grippers for smooth and uncontaminated objects of manipulation, which prevents vacuum breaking during gripping.…”

Section: Classification Of Vgdsmentioning

confidence: 99%

A Systematic Review on Pneumatic Gripping Devices for Industrial Robots

et al. 2022

View full text Add to dashboard Cite

Based on the literature review, the article presents the analysis of approaches to classifying Gripping Devices (GDs) of Industrial Robots (IRs) and substantiates the need for systematising Pneumatic GDs (PGDs). The authors propose a classification of well-known PGDs, in which the holding force of the Manipulated Object (MO) is formed under the action of gas-dynamic effects. A general classification of PGDs with features common to all PGD subtypes is proposed: PGD type; contact type; object base type; object centring type; specialisation type; working range; availability of additional devices; the number of grippers; type of control; type of attachment to the robot. Each feature of the general PGD classification, which affects PGD characteristics, is analysed, and a usage example is given. The advantages of each feature included in the general PGD classification are also considered. For a more detailed classification, PGDs are divided into the following types: Vacuum GDs (VGDs), Jet GDs (JGDs), Combined PGDs (CPGDs). For VGD, the main distinguishing features are highlighted, which are the vacuum creation method, effect/actuator, stepwise nozzle, suction cup type, suction material type. The main distinguishing features of JGDs include using a jet of compressed air, the shape of nozzle elements, the number of nozzle elements, the direction of gas flows, type of surface of the MO. The main distinguishing features of CPGD include the type of combination and function performed. The main features are given for each classification, and the advantages/disadvantages of the most typical representatives of GDs are described. The authors identify the main development directions for GDs at the present stage of robotisation of production processes, medicine, military and space technology, etc. Based on the analysis and systematisation of literature data, the authors define the main promising areas of research that will be actively developed soon: optimisation of grippers’ design, flexible grippers, additive manufacturing (3D-printing) when creating grippers, collaborative grippers, modular grippers, universal grippers, grippers based on new materials, new effects in grippers, bionic and medical grippers, simulation and rendering of the gripping process.

show abstract

Section: Classification Of Vgdsmentioning

confidence: 99%

A Systematic Review on Pneumatic Gripping Devices for Industrial Robots

et al. 2022

View full text Add to dashboard Cite

show abstract

“…These studies put much emphasis on the effect of various geometrical aspects on the ejector's performance. However, in some complex technical systems that use high-temperature fluids, such as ramjet engines, gas turbines, and some other applications, the use of annular-nozzle and multi-nozzle ejectors is promising for reducing the length of the mixing chamber and enhancing the entrainment performance [26][27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Efficiency Optimization of an Annular-Nozzle Air Ejector under the Influence of Structural and Operating Parameters

Lysak

Konyukhov

et al. 2023

Mathematics

View full text Add to dashboard Cite

The efficiency of annular-nozzle ejectors serving as components of complex technical systems interacting with high-temperature media in engines and in the field of energy technologies is not linearly related to the gas-dynamic characteristics of the flows formed in the device. In this paper, we have analyzed the results of numerical and experimental studies of gas jets in an annular-nozzle air ejector. The regression equations built according to the circumscribed central composite design described the relationship between a pressure drop and the structural parameters of the nozzle with the speed and mass flow rates of the airflows, including error rates of no more than 15 percent. A two-factor optimization based on Harington’s generalized desirability function was performed to obtain a relatively accurate estimate of the ejector efficiency under the influence of the structural and operating parameters. An optimization method based on the combination of response surface methodology and the desirability function approach, allowing simultaneous consideration of all responses, made it possible to simultaneously optimize multiple conflicting objectives.

show abstract

“…T-II: When a water-droplet or water-flow reached the shed edge, the liquid moved close to the chamfering of the shed edge (direction B) due to the Coanda Effect [21]. Furthermore, suspended water-drops formed on the lower surface close to the edge, as shown schematically in Figure 9.…”

mentioning

confidence: 98%

Discharge Behavior and Morphological Characteristics of Suspended Water-Drop on Shed Edge during Rain Flashover of Polluted Large-Diameter Post Insulator

et al. 2021

View full text Add to dashboard Cite

Rain is one of the dominant meteorological factors threatening the outdoor insulation performance of ultra-high voltage (UHV) power stations. Discharge occurring on the polluted surface of post insulators in rain has always been a major concern of power stations. Previous studies have shown that suspended water droplets on the shed edge play an important role in the rain flashover process. In this work, artificial contamination rain flashover tests were carried out in a laboratory on a UHV DC (Ultra-High Voltage Direct Current) large-diameter composite post insulator, which had a rod diameter of 625 mm and alternating sheds (105 mm and 75 mm for larger and smaller shed overhang, respectively). The discharge mechanism was analyzed base on the observation of discharge phenomenon of suspended water-drops on the shed edge. Moreover, simulation models by COMSOL Multiphysics were established to investigate the electric field around sheds and suspended water-drops, as well as the shape change of water droplets on the insulation surface, especially at the edge of the shed. Results show that the shape parameters of water-droplets changed continuously under the combined action of gravity, surface tension, and capillary tension. Suspended water-droplets on the shed edge showed a great influence on the electric field distribution, and the resulting discharge lead to the bridging between sheds. This work paves a new way to revealing the contamination rain flashover mechanism on post insulators and provides critical knowledge for power stations on preventing flashover accidents.

show abstract

Optimisation Analysis of Structural Parameters of an Annular Slot Ejector Based on the Coanda Effect

Cited by 3 publications

References 27 publications

A Systematic Review on Pneumatic Gripping Devices for Industrial Robots

A Systematic Review on Pneumatic Gripping Devices for Industrial Robots

Efficiency Optimization of an Annular-Nozzle Air Ejector under the Influence of Structural and Operating Parameters

Discharge Behavior and Morphological Characteristics of Suspended Water-Drop on Shed Edge during Rain Flashover of Polluted Large-Diameter Post Insulator

Contact Info

Product

Resources

About