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Spray Formation and Droplet Behavior
Published in Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong, Combustion Engineering, 2022
Kenneth M. Bryden, Kenneth W. Ragland, Song-Charng Kong
The volume mean diameter (VMD or d¯3) is the average diameter based on the fraction of droplets with a given volume. VMD=d¯3=∑i=1∞di3ΔNi13
State of the Art and Perspectives in Membranes for Membrane Distillation/Membrane Crystallization
Published in Andreas Sapalidis, Membrane Desalination, 2020
Carmen Meringolo, Gianluca Di Profio, Efrem Curcio, Elena Tocci, Enrico Drioli, Enrica Fontananova
VMD configuration is usually used to separate volatile organic compounds from aqueous solutions. Some specific applications include treatment of water containing different types of dyes [33], removal of ammonia from dilute aqueous solutions [32, 34], and seawater desalination [35]. In VMD, a vacuum pump is utilized to create a vacuum in the distillate side. To transport the water vapor, the vacuum pressure applied must be lower than the saturation pressure of the evaporating species. Condensation occurs outside of the membrane module. A great advantage of this configuration is that the heat lost by conduction is negligible [8].
SVD-VMD algorithm and its application in leak detection of natural gas pipeline
Published in Petroleum Science and Technology, 2022
Hong Li, Lixin Chu, Jingyi Lu, Qingqiang Liu, Fu Li, Kun Zhang
The VMD algorithm is not self-adaptive decomposition, many parameters need to be preset in actual application. Meanwhile, the decomposed effects highly depend on the selection of the number of sub-modes K. Indeed, optimization algorithms are more and more popular and can be applied to various optimization problems. Differential evolution (DE) has always been studied in the field of optimization problems. In order to overcome the premature convergence and low search ability, Deng has proposed the enhanced MSIQDE algorithm with novel multiple strategies for global optimization problems and demonstrate the optimization performance by comparing others methods (Deng et al. 2022) It also aims at the slow convergence speed and weak search ability of QEA algorithm, Deng et al. have proposed an improved QEA with cooperative coevolution framework and hybrid mutation strategy (HMCFQDE) for large scale optimization (Deng et al. 2021). The arithmetic optimization algorithm (AOA) is a kind of optimization algorithm proposed by Abualigah et al. (2021), which exhibits high convergence and coverage (Abualigah et al. 2021). In fact, many optimization algorithms have been combined with VMD to optimize VMD parameters and achieve better results. In Gu et al. (2020), an adaptive VMD for diagnosing incipient fault of rolling bearings has been presented and the parameters of VMD have been determined by minimum mean envelope entropy. Li et al. (2020) have proposed that the envelope kurtosis maximum as an index to optimize and determine the mode number of VMD and it has achieved perfect effects. In Diao et al. (2020), a new type of fitness function has proposed, which is composed of maximum entropy (ME). The ME has been reached a preferable search result and has been implemented in leak detection. In Lu (Lu et al. 2021) have proposed that an improved VMD based on the optimization of salp swarm algorithm (SSA) for denoising of natural gas pipeline leakage signal. The ratio of mean and variance of the permutation entropy (PE) is used for the fitness function of SSA, and the control parameter K of VMD is selected by SSA.