Analysis Of Internal Flow Field Research Articles

Multi-Objective Optimization of the Hydrodynamic Performance of the Second Stage of a Multi-Phase Pump

Most multi-phase pumps used in crude oil production have been developed to satisfy certain pressure specifications. In the design of these pumps, the flow characteristics of the posterior stage are different from those of the prior stage. For this reason, the design of the second stage needs to be supplemented. To optimize performance in this stage, multi-objective optimization to simultaneously increase pressure and efficiency is reported in this article. Flow analyses of the single and multiple phases of the multi-phase pump were conducted by solving three-dimensional steady Reynolds-averaged Navier–Stokes equations. For the numerical optimization, two design variables related to the blade inlet angle were selected. The impeller and the diffuser blades were optimized using a systematic optimization technique combined with a central composite method and a hybrid multi-objective evolutionary algorithm coupled with a surrogate model. The selected optimal model yielded better hydrodynamic performance than the base model, and reasons for this are investigated through internal flow field analysis.

냉열발전을 위한 극저온 체크밸브의 유동해석

Abstract: Swing check valve is opened when the flow direction is forward, when the flow is reversed, the valve is automatically closed by back pressure. In this study, the internal flow field analysis of the valve was conducted by Fluent. The working fluid used in the study, using liquefied methane -165 ℃ (CH4) and velocity field, pressure field, pressure drop coefficient were simulated by varying separately the opening divergence into four intervals from 0 to 100%. The approximate research result are as follow : When the opening divergence is smaller, it appears high pressure on the upstream side, this value is relaxed when the opening divergence is large. Flow rate coefficient of the valve shows a larger value as the degree of opening becomes larger, confirming that the check valve used in the study is in the effective flow rate counting range. Key Words ：Cryogenic, LNG, Swing Check Valve, Flow Analysis, Flow Coefficient, Pressure Drop Coefficient *†문정현(교신저자) : 선박해양플랜트연구소 해수플랜트연구센터E-mail : moonjh@kriso.re.kr, Tel : 033-630-5028 *†Jung-Hyun Moon(corresponding author) : Korea Research Institute of Ships & Ocean Engineering, Seawater Utilization Plant Research CenterE-mail : moonjh@kriso.re.kr, Tel : 033-630-5028

Internal Flow Field Analysis of Engine Intake Manifold Based on RE and CFD

The performance of the engine air intake system directly affect the working performance and fuel consumption, where the intake manifold design is the key.In this paper aimed at L91 Engine intake manifold ,firstly theRE(Reverse Engineering)technology was usedto rebuild the3d model of intake manifold.And then the internal flow zoneof the intake manifoldwas meshedin the pre-processing software ICEMand the internal flow fieldwas analyzedin the softwareof Fluent.The numerical model was verified by comparing the simulated and measured results. And then based on the numerical analysis of the internal flow characteristics of the intake manifold, the structure of variable-length intake manifold was come up with and finally was numerically proved to be better than the normal one.

The Numerical Simulation Analysis of Flow Field in Level Control Valve of Water Storage Tank

Level control valve of water storage tank is installed in the outlet of tank, which control the water level of water storage tank by adjusting the water emissions, which make great significance for the safe operation of the super (super) criticality thermal power unit boiler . Complete the simulation analysis of internal flow field by the method of numerical simulation ,in order to achieve structure improvements of level control valve of water storage tank, that make level control valve of water storage tank better meet the work requirements. Establish flow channel model and mesh models of level control valve of water storage tank in various stages of the open process. Make three dimensional viscous numerical simulation of the internal complex flow field by the computational fluid dynamics software of ANSYS CFX. The error between the simulation values of the flow coefficient and the theoretical values , trial values is less than 5% ,which verifies the correctness of the simulation results . Get pressure contour , velocity streamline diagrams and outlet mass flow of level control valve of water storage tank in various stages of the open process. According to the pressure contours and velocity streamline diagrams, make detailed analysis of the flow field of level control valve of water storage tank. According to the dates of outlet mass flow, fit the flow characteristic curve of level control valve of water storage tank. Provide a theoretical basis for the structural design of level control valve of water storage tank.

The Optimal Research on Impeller Central Location of Centrifugal Fan

Taking the G4-73№8D centrifugal fan as research object and utilizing the software of NUMECA to simulate flow fields of volutes with different radial relative positions, the optimum central location of the fan impeller was obtained. The contrastive analysis of internal flow field which of the original and impeller center location optimization fan was under the rated and variable condition, showed that the optimized fan enhanced impeller and volute casing radial adaptive and the efficiency and export static pressure of optimized fan were improved.

The Research of Internal Corrosion Location Prediction Technology in the Typical Pipeline Components of Natural Gas Gathering Pipeline

Gathering pipeline is used for transporting crude gas without purification in natural gas mine, it has short transmission distance, small diameter, pressure changes and other characteristics . In the natural gas gathering and transportation process, the carrying effect of high pressure and high speed gas, water, sand, acidic medium and other untreated impurities could induce flow corrosion in gas pipeline, pipeline components (referred to as the tube), and other ancillary facilities interior. According to the actual failure case of an acidic gas mine pipeline, based on the CO2 corrosion mechanism, internal flow field analysis of the model and the actual test results, through comparison of numerical results and actual test results, the article gives a research on corrosion location prediction technology in the typical components of natural gas gathering pipeline. The technology has an important significance to guide field inspection, improve the detection efficiency and defect detection rate, and protect the natural gas mine gathering safety.

The CFD Analysis of Internal Flow Field in Turbocharger Compressor

In this paper, the 3D flow analysis model of gasoline engine turbocharger compressor was built by using the software NUMECA. The flow fields of the vaneless diffuser and volute, such as airflow velocity field, temperature field, pressure field and the entropy field were simulated. The internal flow performance of the vaneless diffuser and volute were analyzed. The simulation results show that the field changes accord with the compressor characteristics, thus the vaneless diffuser and volute of the compressor design is reasonable. The approach of numerical simulation and flow field analysis by using CFD method can accurately predict the compressor performance. The research methods and conclusions provide theoretical and practical reference for the optimization design of the compressor.

Numerical Simulation and Analysis of Internal Flow Field for Control Valve Inlet Blocking Fault

The internal flow field and the noise of inlet blocking fault and trouble-free for control valve are numerical simulated by CFD. The study shows that it is a greater influence on the internal flow field by inlet blocking, the back-end of stemming appears reverse flow, and it make vortex, the phenomenon of the two fluids mixing is appeared below the valve core. The tremendous noise is appeared in the blocking, and it increases the noise of the surrounding area.

The Calculation and Analysis of the Yacht Engine Cooling Water Jacket Based on the CFD Technology

The paper takes a yacht engine as the research object. Build a three dimensional model of one yacht engine cooling water jacket through the Pro/E software. Make analysis of internal flow field of cooling water distribution, pressure loss, and so on, with the computational fluid dynamics software—STAR-CCM+. Find problems in the cooling system, and propose improvements for the engine cooling water jacket and evaluate the program and conduct a comparative analysis of the original program.

Analysis of Internal Flow Field for Centrifugal Fan in Series

Centrifugal fan in series with high wind pressure is the key facility of pneumatic transport equipment. To consider the impact of changed conditions on performance of centrifugal fan, internal flow of three-stage centrifugal fan at rated speed in different total pressure conditions is analyzed by CFD software FLUENT6.3 in this paper. Flow characteristics are obtained and the differences of total pressure and velocity distribution in each impeller are analyzed under different conditions, velocity distribution on the meridian plane and section of wind guide plates are compared. Finally, curves of P-Q and P-η at 4600 r/min are forecasted through the analysis of the data, which provide references for reducing impact that condition alteration on fan performance and improving the efficiency of the fan.

Unified Analysis of Internal Flowfield in an Integrated Rocket Ramjet Engine. II: Ramjet Sustainer

AbstractThe flow and combustion dynamics in the ramjet sustainer of an integrated rocket-ramjet (IRR) engine are investigated systematically. The physical model includes the entire engine flowpath, from the freestream in front of the inlet to the exit of the exhaust nozzle. The flowfield obtained previously is used as the initial condition for the present analysis, so that the complete operation history of the engine can be obtained. Various physiochemical processes dictating the engine internal flow development and flame behavior are examined. Emphasis is placed on the interactions between the inlet and combustion dynamics, as well as the overall engine performance. The key mechanisms for driving and sustaining the flow oscillations are explored. In addition, the acoustic wave structures in the engine flowpath are identified.

Unified Analysis of Internal Flowfield in an Integrated Rocket Ramjet Engine. I: Transition from Rocket Booster to Ramjet Sustainer

AbstractA comprehensive numerical analysis was conducted to study the internal flow development in an integrated rocket-ramjet (IRR) propulsion system. The study consists of two parts: transition from the rocket booster to the ramjet sustainer and combustion dynamics during ramjet operation. The physical model of concern includes the entire IRR flow path, extending from the leading edge of the inlet center body through the exhaust nozzle. The theoretical formulation is based on the Farve-averaged conservation equations of mass, momentum, energy, and species concentration in axisymmetric coordinates and accommodates finite-rate chemical kinetics and variable thermophysical properties. Turbulence closure is achieved using a low-Reynolds-number κ-e two-equation model. The governing equations are solved numerically by means of a finite-volume preconditioned flux-differencing scheme capable of treating a chemically reacting flow over a wide range of Mach numbers. Various important physiochemical processes invo...

Numerical Analysis of Internal Flow Field in an Impeller with the Time Marching Method

Centrifugal compressors are power machineries used widely. Fully understanding of the complex three-dimensional flow field is very important to design higher pressure ratio, higher efficiency centrifugal compressor. In this paper, time marching method is adopted to solve the three-dimensional viscous N-S equations under the relative coordinate system. The internal flow field of the “full controllable vortex” high speed centrifugal impeller is analyzed and the medial velocity vector distribution and the development of the velocity of each section in the impeller are showed. From the figures, it can be seen that the “wake” phenomenon, such as Ecckart described, caused by the curvature, Coriolis force and the boundary layer is exist

The Analysis of Internal Flow Field in Oil-Gas Separator

Movement of the fluid in oil-gas separator has been studied by the method of numerical simulation. It uses the RSM turbulence model and finite volume method for model solution. And QUICK difference scheme and the pressure interpolation format of PRESTO are used. Iterative solution of velocity field utilizes the SIMPLE algorithm. Through analysis of internal velocity field, pressure field and flow line in the oil-gas separator, it reveals the flow mechanism of separators, providing theoretical basis for optimization and design of new separators in the future.

Solid Propellant Grain Design and Burnback Simulation Using a Minimum Distance Function

DOI: 10.2514/1.22937 A fast computational method for simulating the evolution of the burning surface of a complex, three-dimensional solid rocket motor propellant grain has been developed using a signed minimum distance function. The minimum distance function is calculated using stereo-lithography surface information from a computer-aided-design file and propellant surface burnback is simulated by manipulation of the initial minimum distance function. Variable time steppingandmultiplespatialgridsfurtherreducecomputationtimerequirements. Resultsindicatethatthismethod gives adequate accuracy with acceptable computation time for time scales of the full motor burn. The resulting code (Rocgrain) allows for motor grain design by user-friendly commercial computer-aided-design programs and for coupling with internal flow codes. This enables a single geometric tool to be used for describing the propellant grain geometry for both grain design and internal flowfield analysis. The Rocgrain code can be coupled with a variety of flowfield codes ranging in complexity from simple zero-dimensional to more sophisticated computational fluid dynamics analysis (e.g., nonlinear acoustic instability).