Effect of nozzle exit position (NXP) on variable area mixing ejector

Kumar, Virendra; Subbarao, P.M.V.; Singhal, Gaurav

doi:10.1007/s42452-019-1496-y

Cited by 11 publications

(4 citation statements)

References 15 publications

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“…Entrainment is a crucial ejector performance characteristic that is affected by a number of design and operational factors, including the operating temperature [20][21][22], pressure [23,24], nozzle geometry [25,26] and its exit position [27][28][29], mixing chamber geometry [30][31][32][33], and operating uids [34]. The ratio of the entrained mass ow rate of secondary uid to the motive mass ow rate of primary uid is known as the entrainment ratio [35].…”

Section: Introductionmentioning

confidence: 99%

An Experimental Comparative Performance Study of Variable Area Ejectors in Different Operating Conditions

Kumar,

Subbarao

2024

Preprint

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This research experimentally compares the performance of two variable area ejectors designed based on the Constant Rate of Momentum Change (CRMC) approach and the Constant Rate of Kinetic Energy Change (CRKEC) approach. Ejector systems were designed for specific design and operating conditions to perform experiments. The pressure recovery ratio (PRR) and entrainment ratio (ω) at on-design operating conditions were compared using the experimental results. The study also optimized the entrainment ratio of both systems at off-design conditions. The results indicate that both variable-area ejectors based on CRMC and CRKEC have their own advantages and limitations in terms of performance and suitability for specific applications. CRMC ejectors provide higher entrainment ratios (0.512) and lower pressure recovery ratios (0.178), while CRKEC ejectors provide slightly higher pressure recovery ratios (0.18) and lower entrainment ratios (0.5) at on-design conditions. Furthermore, the study investigated the off-design impact of nozzle exit positions (NXPs) and the pressure of motive and secondary flows on the entrainment ratio of both ejectors.

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Section: Introductionmentioning

confidence: 99%

An Experimental Comparative Performance Study of Variable Area Ejectors in Different Operating Conditions

Kumar,

Subbarao

2024

Preprint

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“…On the other hand, the effect of the primary nozzle has been experimentally analyzed by Thongtip and Aphornratana 18 . Kumar et al 19 have done an extensive study on the effect of nozzle exit position and they have used entrainment ratio as the parameter to quantify the ejector performance. A similar approach was implemented for the current study.…”

Section: Introductionmentioning

confidence: 99%

Design optimization of ejectors using ANN and GA

et al. 2022

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Ejectors are devices that are based on the principle of momentum transfer. A primary fluid passes through a nozzle that is usually of converging–diverging cross‐section so that the flow reaches supersonic velocity at the exit. Consequently, a low‐pressure region is created just outside the nozzle exit. This pressure gradient draws out the secondary fluid, into the ejector through the annular space—a phenomenon known as entrainment. This paper attempts to design and optimize an ejector with 1,1‐dichloro‐1‐fluoroethane as the working fluid. The governing equations that accurately predict the behavior of the working fluid, are solved using the finite volume method after the discretization of the flow domain, using ANSYS Fluent. A database is created over 1008 similar computational fluid dynamics simulations by recording the input parameter values and the corresponding output parameter values. It is then used to define a function that can precisely predict the output for an unknown set of input parameters. This is achieved through the implementation of artificial neural networks—a surrogate modeling technique. The accuracy of the model is determined from the coefficient of correlation. The objective function thus obtained is optimized with the help of a genetic algorithm (GA)—a nature‐inspired optimization technique. The optimal design of the ejector for a set of operating conditions is obtained as the output of the GA.

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“…Though, the performance of the supersonic ejector is a function of geometrical and operating parameters. Plenty of literature has been proposed to understand the impact, including design approaches (Seehanam et al 2007;Kumar et al 2019), geometrical parameters (Li et al 2019;Zhu et al 2009;Wu et al 2018;Lin et al 2013), and operating parameters (Huang et al 1985;Shestopalov et al 2015;Aidoun and Ouzzane 2004;Vereda et al 2012) in different fields of applications for various working fluids (Croquer et al 2017;Cardemil and Colle 2012;Zhu and Jiang 2014) at on/off design conditions. The computational fluid dynamics (CFD) tools play an essential job in ejector design optimization and performance evaluation.…”

Section: Introductionmentioning

confidence: 99%

Analytical and Numerical Study on the Performance of ‎Supersonic Ejector at Different Operating Conditions ‎and Working Fluids

2021

JAFM

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The computation of ejector geometry for a given fluid is essential and plays a crucial role in creating an ejector profile and performance analysis. The current paper discusses the constant rate of momentum change (CRMC) approach using a real gas equation for ejector design. The numerical analysis is carried to validate the analytical geometry and the effect of operating parameters on the entrainment ratio. The variation in entrainment ratio for the different working fluids has also been studied on the geometry computed for water-vapour. It is observed that the entrainment ratio of the ejector significantly varies with the change in operating conditions and working fluids. The numerically predicted entrainment ratio is ~0.354 compared to the on-design entrainment ratio 0.4 for water vapor, while the predicted entrainment ratio for other working fluids is ~0.319, ~0.314, and ~0.36 for air, N2, and CO2, respectively.

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Effect of nozzle exit position (NXP) on variable area mixing ejector

Cited by 11 publications

References 15 publications

An Experimental Comparative Performance Study of Variable Area Ejectors in Different Operating Conditions

An Experimental Comparative Performance Study of Variable Area Ejectors in Different Operating Conditions

Design optimization of ejectors using ANN and GA

Analytical and Numerical Study on the Performance of ‎Supersonic Ejector at Different Operating Conditions ‎and Working Fluids

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