scholarly journals Water aeration researches using fine air bubble generators

2022 ◽  
Vol 960 (1) ◽  
pp. 012018
Author(s):  
Nicolae Vlad Sima ◽  
Nicolae BĂran ◽  
Nicoleta Dorina Albu ◽  
Mihaela PetroȘel ◽  
Mihaela Constantin
Keyword(s):  
Experimental Data ◽  
Oxygen Transfer ◽  
Water Mass ◽  
Experimental Results ◽  
Atmospheric Air ◽  
Air Bubble ◽  
Fine Bubble ◽  
Experimental Researches

Abstract The paper presents experimental researches able to demonstrate that the aeration installations with mobile fine bubble generators are more efficient than the classic ones with fixed, fine bubble generators. The paper develops water aeration researches by introducing two types of fine air bubble generators: I. Fixed fine air bubble generators, which generate Ø <1 mm bubbles; II. Mobile fine air bubble generators that move in the volume of water subject to aeration. The theoretical and experimental results are presented for the two versions. According to experimental data, aeration with mobile FBG is more efficient in terms of oxygen transfer from atmospheric air to a stationary water mass.

Some Consideration Regarding the Models for Collisions with Plastic Indentation

2014 ◽  
Vol 658 ◽  
pp. 161-166 ◽  
Author(s):  
Stelian Alaci ◽  
Florina Carmen Ciornei ◽  
Constantin Filote
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Comparative Study ◽  
Experimental Results ◽  
Plastic Deformations ◽  
Plastic Indentation ◽  
Impact Parameters ◽  
Experimental Researches ◽  
Theoretical Results ◽  
Collision Models

The paper presents a comparative study between experimental results for a collision with plastic deformations and a theoretical model from literature. A review of collision models is briefly made and a theoretical model is selected after an analysis between theoretical results and data from experimental researches. The theoretical results are evaluated versus experimental data from laser scanned post collision indentations, for the ball-plane impact. The theoretical model requires improvements by considering additional impact parameters.

scholarly journals Researches on the delimitation between the water aeration and oxygenation processes

2020 ◽  
Vol 180 ◽  
pp. 01002
Author(s):  
Rasha Cusma ◽  
Nicolae Băran ◽  
Nicolae Vlad Sima ◽  
Mihaela Petroşel ◽  
Remus Voicu ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Gaseous Mixture ◽  
Experimental Results ◽  
Atmospheric Air ◽  
Experimental Researches

Considering that in certain papers the aeration processes are confused with the oxygenation processes, a distinction between them must be made. The paper presents modern water aeration and oxygenation installations. The experimental results obtained for the two categories of installations are highlighted. Theoretical and experimental researches aim to increase the concentration of dissolved oxygen in water; this can be done in two ways: I - by introducing atmospheric air into the water; II - by introducing a gaseous mixture consisting of atmospheric air and oxygen. Version II is better, the results being shown in Figure 11.

scholarly journals Influence of Fine Bubble Generator Architecture on Time Variation of Dissolved Oxygen Concentration in Water

2019 ◽  
Vol 70 (6) ◽  
pp. 2132-2135
Author(s):  
Nicolae Baran ◽  
Mihaela Constantin ◽  
Beatrice Tanase ◽  
Edgar Moraru ◽  
Corina Ioana Moga
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Time Variation ◽  
Experimental Results ◽  
Dissolved Oxygen Concentration ◽  
Fine Bubble ◽  
Experimental Researches ◽  
Good Coincidence

The paper presents two constructive solutions in the field of fine bubble generators that serve to aerate the water. Two installations for experimental researches have been designed and built in connection with the two constructive solutions. The dissolved oxygen concentration was experimentally determined. The theoretical and experimental results for the two constructive solutions are compared showing a good coincidence in relation to the results reported in the literature.

INFLUENCE OF A HORIZONTAL FLOW ON THE PERFORMANCE OF FINE-BUBBLE DIFFUSED AIR SYSTEMS

1994 ◽  
Vol 30 (4) ◽  
pp. 89-96 ◽  
Author(s):  
G. Da Silva-Deronzier ◽  
Ph. Duchene ◽  
C. Ramel
Keyword(s):  
Oxygen Transfer ◽  
Horizontal Flow ◽  
Air Bubbles ◽  
Empirical Knowledge ◽  
Oxidation Ditch ◽  
Spiral Flow ◽  
Air Bubble ◽  
Fine Bubble ◽  
Flow Phenomena ◽  
Exchange Surface

The horizontal rotation of water in an oxidation ditch by separate agitation improves the oxygen transfer of diffused air aeration systems. This can be explained by the modifications. due to the horizontal flow. of several parameters that play a role in the oxygen transfer. An experimental study was performed on a 1400m3 annular ditch fitted with fine bubble diffusers and mixers to quantify this empirical knowledge. The initial findings of this research are presented. Compared to the absence of an imposed horizontal flow, the O2 mass transferred per hour, in clean water, is increased by 40% to 50% for a horizontal water flow of 0.4 to 0.5 m/s. This improvement may be explained by the prolongation of air bubble contact time (modification of spiral flow phenomena) for 10% at the most, by the increase of the exchange surface for the most part, due, not to the shear or to the elimination of the coalescence of air bubbles, (insignificant phenomena in this case). but to the deformation of air bubbles for 17% at the most and especially to the decrease of the diameter of the nascent bubbles. Moreover, the renewal of the liquid layer around the air bubbles could be considered as insignificant.

Experimental Researches on Detonation of Aluminized Explosives to High-Speed Flyer Impact

2010 ◽  
Vol 152-153 ◽  
pp. 713-716
Author(s):  
Jian Bing Men ◽  
Jian Wei Jiang ◽  
Shu You Wang
Keyword(s):  
Experimental Data ◽  
Plane Wave ◽  
Statistical Method ◽  
Structural Design ◽  
High Speed ◽  
Critical Thickness ◽  
Experimental Results ◽  
Wave Loads ◽  
Experimental Researches ◽  
Selection Of

In present paper, aluminized explosives with separator inside are detonated by plane wave loads from metal flyer impacts. Four types of aluminized explosives(THAL、H-6、HBX-1、HBX-3) that used widely in warheads are test experimentally in order to obtain the critical thickness of separator(thicknesses L50-50% possibility of detonating). The critical separator thicknesses of detonating four types of aluminized explosives are calculated through statistical method according to experimental data. Stability sequence for these four explosive were determinate according to anti-detonation capability. The experimental results provided reference for the selection of explosive and structural design of warhead.

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

Validating Numerical CFD Simulations With Experimental Data for Turbulence Phenomena in Axial Flow Gas Turbine Diffusers

2009 ◽  
Author(s):  
Farrokh Zarifi-Rad ◽  
Hamid Vajihollahi ◽  
James O’Brien
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Axial Flow ◽  
Experimental Results ◽  
Scale Model ◽  
Data Set ◽  
Pressure Profiles ◽  
Scale Models ◽  
Inlet Conditions

Scale models give engineers an excellent understanding of the aerodynamic behavior behind their design; nevertheless, scale models are time consuming and expensive. Therefore computer simulations such as Computational Fluid Dynamics (CFD) are an excellent alternative to scale models. One must ask the question, how close are the CFD results to the actual fluid behavior of the scale model? In order to answer this question the engineering team investigated the performance of a large industrial Gas Turbine (GT) exhaust diffuser scale model with performance predicted by commercially available CFD software. The experimental results were obtained from a 1:12 scale model of a GT exhaust diffuser with a fixed row of blades to simulate the swirl generated by the last row of turbine blades five blade configurations. This work is to validate the effect of the turbulent inlet conditions on an axial diffuser, both on the experimental front and on the numerical analysis approach. The object of this work is to bring forward a better understanding of velocity and static pressure profiles along the gas turbine diffusers and to provide an accurate experimental data set to validate the CFD prediction. For the CFD aspect, ANSYS CFX software was chosen as the solver. Two different types of mesh (hexagonal and tetrahedral) will be compared to the experimental results. It is understood that hexagonal (HEX) meshes are more time consuming and more computationally demanding, they are less prone to mesh sensitivity and have the tendancy to converge at a faster rate than the tetrahedral (TET) mesh. It was found that the HEX mesh was able to generate more consistent results and had less error than TET mesh.

Heats of mixing of binary mixtures of pyridine base with n-alkane

1988 ◽  
Vol 66 (7) ◽  
pp. 1625-1627 ◽  
Author(s):  
Teresa Kasprzycka-Guttman ◽  
Juan H. Vera
Keyword(s):  
Experimental Data ◽  
Binary Mixtures ◽  
Experimental Results ◽  
Pyridine Base ◽  
Heats Of Mixing

Heats of mixing of 2,4-lutidine and 2,4,6-collidine with n-alkanes were measured at 293.15 K using an isothermal dilution calorimeter. Experimental results were fitted with a Redlich–Kister polynomial. Experimental data and coefficients for the Redlich–Kister polynomials are reported.

A Statistical Adaptable Distribution Function Model for Low Probabilities of Failure

1993 ◽  
Author(s):  
Suryaji R. Bhonsle ◽  
Paul Thompson
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Experimental Results ◽  
Function Model ◽  
Log Normal ◽  
Function Models

Abstract Weibull, log normal, and some other Distribution function models (D.F.M.) have a tendency to deviate from experimental results. This deviation, either exceedingly conservative or nonconservative, is amplified at low probabilities of failure. To remedy such problems a new D.F.M. is derived. It is then used to predict low probabilities of failure. The predictions are consistent with experimental data and are not too conservative or too nonconservative.

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