scholarly journals A mathematical model of the controlled axial flow divider for mobile machines

2016 ◽  
Vol 134 ◽  
pp. 012039 ◽  
Author(s):  
V L Mulyukin ◽  
D L Karelin ◽  
A M Belousov
Keyword(s):  
Mathematical Model ◽  
Axial Flow ◽  
Flow Divider

scholarly journals Development of the Method for Predicting and Calculating the Operation of Sorption Systems for Cleaning the Generator Gas based on Dolomite Use. Part II

2021 ◽  
pp. 31-42
Author(s):  
Mihail Malko ◽  
◽  
Sergey Vasilevich ◽  
Andrei Mitrofanov ◽  
Vadim Mizonov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Axial Flow ◽  
Thermochemical Conversion ◽  
Local Exchange ◽  
Direct Combustion ◽  
Calculation Step ◽  
Current Characteristics ◽  
The One ◽  
Generator Gas ◽  
Sorption Systems

At present, instead of a direct combustion of solid fuel, its thermochemical conversion is exten-sively used to produce a generator gas. The use of this technology is connected with the need for gas purification. One of the promising and widely spread sorbents for the purification of the generator gas is dolomite, whose particles compose the active component of the bed filters. Forecasting the technological characteristics of the functioning of the bed filters of a various de-sign is an extremely urgent task. The objective of the study is to develop a method for forecast-ing and calculating the operation of sorption systems for purification of the generator gas based on dolomite. It is achieved by constructing and verifying a mathematical model of the function-ing of the bed sorption filter with a radial-axial flow pattern of the generator gas through the do-lomite filling. The Markov chains theory of a mathematical apparatus is used to design the one-dimensional mathematical model of the process with discrete space and time. The main recurrent balance ratio is formed at each calculation step taking into account the current characteristics of the process, which makes the model nonlinear. The significance of the research is that an approach to the problem of increasing the reliability of the description and reliability of forecasting technological processes in a bed filter was proposed based on the construction of mathematical models of these processes, in which the filter is considered as a system with distributed characteristics, and the calculation was based on local exchange potentials between particles and gas.

Mathematical Model of a Throttle Flow Divider with an Elastic Regulating Element

2021 ◽  
pp. 207-216
Author(s):  
Alexander Rybak ◽  
Roman Gorbunov ◽  
Anastasiya Olshevskaya ◽  
Natia Ugrekhelidze ◽  
Marina Egyan
Keyword(s):  
Mathematical Model ◽  
Flow Divider

Steady Expiratory Flow in a Model Symmetric Bifurcation

1994 ◽  
Vol 116 (3) ◽  
pp. 318-323 ◽  
Author(s):  
Yao Zhao ◽  
Baruch B. Lieber
Keyword(s):  
Axial Flow ◽  
Reynolds Numbers ◽  
Small Region ◽  
Cross Sectional ◽  
Flow Divider ◽  
Velocity Peak ◽  
Branching Angle ◽  
Expiratory Flow ◽  
Junction Plane ◽  
Parent Tube

A model symmetric bifurcation was employed to simulate steady expiratory flow in the upper part of the human central airways. A two color, two component laser Doppler anemometer was used to measure both the axial flow and the secondary flow at three different Reynolds numbers of 518, 1036, and 2089, corresponding to Dean numbers of 98, 196, and 395. The test section is a symmetric bifurcation of constant cross-sectional area with a branching angle of 70 degrees. The flow rate into the two daughter branches was about the same. Results show that in the junction plane, velocity profiles in the daughter branches are skewed towards the inner walls. In the parent tube, just downstream of the flow divider, the velocity profile is biconcave with a dip at the center but this is rapidly transformed into a velocity peak. In a plane transverse to the bifurcation plane, parabolic velocity distribution was conserved through the daughter branches. In the parent tube, the transverse profiles became flat downstream of the flow divider and developed a defect at the center further downsteam towards the end of the parent tube part of the bifurcation. The velocity defect was confined to a small region in the vicinity of the centerline. Helical motion typified by symmetric vortices was observed in the daughter branches. In the parent tube, a set of four vortices induced by the turning of the flow was observed.

A Mathematical Model to Analyze the Torque Caused by Fluid–Solid Interaction on a Hydraulic Valve

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Emma Frosina ◽  
Adolfo Senatore ◽  
Dario Buono ◽  
Kim A. Stelson
Keyword(s):  
Mathematical Model ◽  
Closed Loop ◽  
Position Control ◽  
Axial Flow ◽  
Closed Loop Control ◽  
Spin Effect ◽  
Loop Control ◽  
Spin Effects ◽  
Study Results ◽  
Spool Valve

In this paper, a three-dimensional (3D) computational fluid dynamics (CFD) methodology to improve the performance of hydraulic components will be shown, highlighting the importance that a study in the fluid mechanics field has for their optimization. As known, the valve internal geometry influences proportional spool valve hydraulic performance, axial flow forces, and spin effects on the spool. Axial flow forces and spin effects interact directly with the position control performance of a direct actuating closed-loop control valve, reducing its capability. The goal of this activity is the study of the torque on the spool induced by the flow and using a CFD 3D methodology to identify causes of this phenomenon and to find a general mathematical solution to minimize the spool spin effect. The baseline configuration and the new ones of the proportional four-way three-position closed-loop control spool valve have been studied with a mathematical model. The models were also validated by the experimental data performed in the Hydraulic Lab of the University of Naples. In particular, the tests allowed to measure the torque on the spool varying the oil flow rate, using a dedicated test bench layout where the spool was directly connected to a torque meter. Several geometries have been analyzed to find the best one to minimize spool spin behavior while maintaining an acceptable pressure drop. The study results confirmed the significant improvement of overall component performance.

Circumferential Asymmetry in Axial Flow Compressors

1966 ◽  
Vol 70 (670) ◽  
pp. 953-957
Author(s):  
M. D. C. Doyle ◽  
J. H. Horlock
Keyword(s):  
Mathematical Model ◽  
Velocity Profile ◽  
Small Perturbation ◽  
Axial Flow ◽  
Inlet Distortion ◽  
Non Linear ◽  
Axial Flow Compressors

In this paper we are restricting our attention to those cases of circumferential inlet distortion where the distortion of the velocity profile is too large to be described as a small perturbation. Thus any theory describing the flow must use a mathematical model which is non-linear.

scholarly journals Unsteady Flow in a Rigid 3-D Model of the Carotid Artery Bifurcation

1996 ◽  
Vol 118 (1) ◽  
pp. 90-96 ◽  
Author(s):  
C. C. M. Rindt ◽  
A. A. v. Steenhoven
Keyword(s):  
Carotid Artery ◽  
Carotid Sinus ◽  
Three Dimensional ◽  
Axial Flow ◽  
Secondary Flows ◽  
Doppler Velocity ◽  
Carotid Artery Bifurcation ◽  
Deceleration Phase ◽  
Flow Divider ◽  
Flow Phenomena

In the present study, finite element calculations are performed of blood flow in the carotid artery bifurcation under physiological flow conditions. The numerical results are compared in detail with laser-Doppler velocity measurements carried out in a perspex model. It may be concluded that the numerical model as presented here is well capable in predicting axial and secondary flow of incompressible Newtonian fluids in rigid-walled three-dimensional geometries. With regard to the flow phenomena occurring, a large region with reversed axial flow is found in the carotid sinus opposite to the flow divider. This region starts to grow at peak systole, has its maximal shape at minimal flow rate and totally disappears at the start of the acceleration phase. C-shaped axial velocity contours are formed in the deceleration phase, which are highly influenced by secondary flows. These latter flows are mainly induced by centrifugal forces, flow branching, and tapering of the carotid sinus. Lowering the sinus angle, the angle between the main branch and the carotid sinus, results in a smaller region with reversed axial flow.

Sign in / Sign up

Export Citation Format

Share Document