Determination of local hydrodynamic parameters in bubble columns by the electrodiffusion method with oxygen as depolarizer

1994 ◽  
Vol 24 (7) ◽  
pp. 666-669 ◽  
Author(s):  
S. Pannek ◽  
J. Pauli ◽  
U. Onken
Author(s):  
V. I. Pegov ◽  
◽  
I. Yu. Moshkin ◽  

Numerical simulation of the underwater motion of flight vehicles launched from underwater is performed. The updated method of plane sections is used to determine the hydrodynamic parameters of flight vehicles under multiphase flow. Hydrodynamic loading can be evaluated through the determination of nonstationary boundaries of a gas cavity and the linear load on the water-flown aft. By the method of plane sections, the 3D boundary value problem of the cavitational flow of a flight vehicle at an attack angle resolves itself into a plane hydrodynamic problem, separate for each section of the cavity. The predicted results are compared with the experimental data. Validation and verification were performed by comparing the analysis results with the experimental data. The applicability of the method of plane sections to the determination of the hydrodynamic parameters of flight vehicles under multiphase flow is demonstrated.


Author(s):  
Ole A. Eidsvik ◽  
Ingrid Schjølberg

In this paper the hydrodynamic parameters that characterize the behavior of a typical unmanned underwater vehicle are evaluated. A complete method for identifying these parameters is described. The method is developed to give a brief and accurate estimate of these parameters in all six degrees of freedom using basic properties of the vehicle such as dimensions, mass and shape. The method is based on both empirical and analytical results for typical reference geometries (ellipsoids, cubes, etc.). The method is developed to be applicable for a wide variety of UUV designs as these typically varies substantially. The method is then applied to a small observation class ROV. The results are first verified using an experimental method in which the full scale ROV is towed using a planar motion mechanism. An additional verification is performed with numerical simulations using Computational Fluid Dynamics and a radiation/diffraction program. The method shows promising results for both damping and added mass for the tested case. The translational degrees of freedom are more accurate than the rotational degrees of freedom which are expected as most empirical and analytical data are for translational degrees of freedom. The case study also reveals that the relative difference between the numerical simulations and the experimental results are similar to the relative difference between the proposed method and the experiment.


Author(s):  
Nataliaya Kosulina ◽  
Stanislav Kosulin ◽  
Kostiantyn Korshunov ◽  
Tetyana Nosova ◽  
Yana Nosova

The subject matter of the article: Sealed extractor with pressure. The goal of the work: Determination of hydrodynamic parameters of the sealed extractor with pressure. The following tasks were solved in the article: Theoretical research on the creation of a sealed extractor with pressure. It is need to development of ways of implementation and practical recommendations for the given technical solutions in the experimental sample. The following methods are used: Mathematical modeling, differential and integral calculus, experimental research methods. The following results were obtained: The processes occurring in sealed extractors are described mathematically. Parameters that affect the performance of aggregates are determined. Conclusions: As a result of the analysis of the technological process and equipment used in the factories for primary processing of wool, shortcomings and problems are identified and means for their elimination are proposed. It is proposed to use small-sized equipment to work on waste-free technology based on a hydrodynamic pressure extractor. Extraction as an efficient mass transfer process for removing organic components from aqueous solutions has the advantages of low operating temperatures and efficiency. The design features of the sealed pressure extractor are as follows: high angular velocities, the moment of inertia of rotating details, powerful pressure, the presence of nodes that provide a supply and discharge of liquids, tightness. The kinematic and geometric parameters of the rotor affect the sealed extractors’ performance). In sealed extractors, the heavy fraction in the field of centrifugal forces will accumulate on a large radius of the inner side of the rotor and for its movement it is necessary to create an excess pressure at the extractor inlet.


2016 ◽  
Vol 185 (2) ◽  
pp. 259-266
Author(s):  
Ivan A. Kornienko

Modeling by means of SolidWorks Flow Simulation software for determination of hydrodynamic parameters of trawl doors is described by the example of the trawl doors Project 2490 designed by P.P. Augulis.


1979 ◽  
Vol 44 (9) ◽  
pp. 2583-2597 ◽  
Author(s):  
Václav Linek ◽  
Jiří Stejskal ◽  
Jiří Sinkule ◽  
Václav Vacek

A dynamic method for the determination of volumetric mass transfer coefficient of oxygen, kLa, in bubble columns using an oxygen electrode was derived on the basis of a liquid phase axial dispersion model The influence of aeration startup was studied assuming that the kLa value is position and time dependent. The conditions are defined under which the influence of aeration startup and of axial mixing of the liquid upon the steady state kLa value is negligible. A critical assessment has been made of various methods proposed for evaluation of oxygen probe responses.


AIChE Journal ◽  
2004 ◽  
Vol 50 (12) ◽  
pp. 3068-3084 ◽  
Author(s):  
Amol A. Kulkarni ◽  
Jyeshtharaj B. Joshi ◽  
Doraiswami Ramkrishna

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