Utilization of Gas-Liquid Cylindrical Cyclone (GLCC©) Compact Separator for Solids Removal—Part II: Operational Envelope for Carry-Over

2009 ◽  
Author(s):  
S. Omarov ◽  
L. Gomez ◽  
S. Wang ◽  
R. Mohan ◽  
O. Shoham ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mass Flow ◽  
Liquid Velocity ◽  
Solid Mass ◽  
Efficient Operation ◽  
Flow Rates ◽  
Wide Range ◽  
Mass Flow Rates ◽  
Carry Over ◽  
Operational Envelope

The operational envelope for particle (solid and liquid) carry-over (OPEN-CO) in the GLCC© has been studied experimentally and theoretically. The experimental data were acquired for a wide range of flow conditions, including: inlet superficial gas and liquid velocities between 15–35 ft/s and 0.1–1.2 ft/s, respectively, solid particle sizes of 5, 25 and 50 microns, and solid mass flow rates between 6.61lbm/min and 15.43 lbm/min. An uncertainty analysis of the experimental data revealed uncertainties less than 1% and less that 8.5% for the superficial liquid velocity and the superficial gas velocity measurements, respectively. Results from the experimental data show that as the density of the slurry increases (higher solid mass flow rates), the OPEN-CO shifts up. A mechanistic model was developed for the prediction of OPEN-CO, based on particle trajectory. The model assumes that the particle (liquid and solid) density is the same as the slurry density. Model predictions agree well with the experimental data. The developed model can be used for design and efficient operation of the GLCC© for gas-liquid-solid flow (gas slurry separation).

Numerical Analysis of the Flow Inside a Centrifugal Compressor’s Vaneless Diffuser and Volute

2001 ◽  
Author(s):  
Hooman Rezaei ◽  
Abraham Engeda ◽  
Paul Haley
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Mass Flow ◽  
Operating Conditions ◽  
Vaneless Diffuser ◽  
Flow Angle ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Minimum Medium ◽  
Good Agreement

Abstract The objective of this work was to perform numerical analysis of the flow inside a modified single stage CVHF 1280 Trane centrifugal compressor’s vaneless diffuser and volute. Gambit was utilized to read the casing geometry and generating the vaneless diffuser. An unstructured mesh was generated for the path from vaneless diffuser inlet to conic diffuser outlet. At the same time a meanline analysis was performed corresponding to speeds and mass flow rates of the experimental data in order to obtain the absolute velocity and flow angle leaving the impeller for those operating conditions. These values and experimental data were used as inlet and outlet boundary conditions for the simulations. Simulations were performed in Fluent 5.0 for three speeds of 2000, 3000 and 3497 RPM and mass flow rates of minimum, medium and maximum. Results are in good agreement with the experimental ones and present the flow structures inside the vaneless diffuser and volute.

An Experimental Study of the Flow of R-407C in an Adiabatic Spiral Capillary Tube

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
M. K. Mittal ◽  
R. Kumar ◽  
A. Gupta
Keyword(s):  
Experimental Data ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Capillary Tube ◽  
Flow Characteristics ◽  
Flow Rates ◽  
Tube Test ◽  
Mass Flow Rates ◽  
R 134A

The objective of this study is to investigate the effect of coiling on the flow characteristics of R-407C in an adiabatic spiral capillary tube. The characteristic coiling parameter for a spiral capillary tube is the coil pitch; hence, the effect of the coil pitch on the mass flow rate of R-407C was studied on several capillary tube test sections. It was observed that the coiling of the capillary tube significantly reduced the mass flow rate of R-407C in the adiabatic spiral capillary tube. In order to quantify the effect of coiling, the experiments were also conducted for straight a capillary tube, and it was observed that the coiling of the capillary tube reduced the mass flow rate in the spiral tube in the range of 9–18% as compared with that in the straight capillary tube. A generalized nondimensional correlation for the prediction of the mass flow rates of various refrigerants was developed for the straight capillary tube on the basis of the experimental data of R-407C of the present study, and the data of R-134a, R-22, and R-410A measured by other researchers. Additionally, a refrigerant-specific correlation for the spiral capillary was also proposed on the basis of the experimental data of R-407C of the present study.

scholarly journals Verification and Improving the Heat Transfer Model in Radiators in the Wide Change Operating Parameters

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6543
Author(s):  
Mieczysław Dzierzgowski
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Water Mass ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Transfer Model ◽  
Flow Rates ◽  
Wide Range ◽  
Different Types ◽  
Mass Flow Rates

Laboratory measurements and analyses conducted in a wide range of changes of water temperature and mass flow rate for different types of radiators allowed to provides limitations and assessment of the current radiators heat transfer model according to EN 442. The inaccuracy to determinate the radiator heat output according to EN 442, in case of low water mass flow rates may achieve up to 22.3% A revised New Extended Heat Transfer Model in Radiators NEHTMiRmd is general and suitable for different types of radiators both new radiators and radiators existing after a certain period of operation is presented. The NEHTMiRmd with very high accuracy describes the heat transfer processes not only in the nominal conditions—in which the radiators are designed, but what is particularly important also in operating conditions when the radiators water mass flow differ significantly from the nominal value and at the same time the supply temperature changes in the whole range radiators operating during the heating season. In order to prove that the presented new model NEHTMiRmd is general, the article presents numerous calculation examples for various types of radiators currently used. Achieved the high compatibility of the results of the simulation calculations with the measurement results for different types of radiators: iron elements (not ribbed), plate radiators (medium degree ribbed), convectors (high degree ribbed) in a very wide range of changes in the water mass flow rates and the supply temperature indicates that a verified NEHTMiRmd can also be used in designing and simulating calculations of the central heating installations, for the rational conversion of existing installations and district heating systems into low temperature energy efficient systems as well as to directly determine the actual energy efficiency, also to improve the indications of the heat cost allocators. In addition, it may form the basis for the future modification of the European Standards for radiator testing.

scholarly journals Computational study of a radial flow turbine operates under various pulsating flow shapes and amplitudes

2021 ◽  
pp. 1-24
Author(s):  
Ahmed Rezk ◽  
Sidharath Sharma ◽  
S.M. Barrans ◽  
Abul Kalam Hossain ◽  
P. Samuel Lee ◽  
...  
Keyword(s):  
Mass Flow ◽  
Radial Flow ◽  
Pulsating Flow ◽  
Gradual Change ◽  
Maximum Mass ◽  
Flow Rates ◽  
Flow Accumulation ◽  
Wide Range ◽  
Mass Flow Rates ◽  
The Impact

Abstract Radial flow turbines are extensively used in turbocharging technology due to their unique capability of handling a wide range of exhaust gas flow. The pulsating flow nature of the internal combustion engine exhaust gases causes unsteady operation of the turbine stage. This paper presents the impact of the pulsating flow of various characteristics on the performance of a radial flow turbine. A three-dimensional computational fluid dynamic model was coupled with a one-dimensional engine model to study the realistic pulsating flow. Applying square wave pulsating flow showed the highest degree of unsteadiness corresponding to 92.6% maximum mass flow accumulation due to the consecutive sudden changes of the mass flow rates over the entire pulse. Although saw-tooth showed a maximum mass flow accumulation value of 88.9%, the mass flow rates entailed gradual change resulted in the least overall mass flow accumulation over the entire pulse. These two extremes constrained the anticipated performance of the radial flow turbine operates under realistic pulsating flow. Such constraints could develop an operating envelop to predict the performance and optimize radial flow turbines' power extraction under pulsating flow conditions.

scholarly journals Statistical Simulation of Non-Circular Cross Section Poiseuille Flows

2003 ◽  
Author(s):  
Jian-Zheng Jiang ◽  
Ching Shen ◽  
Jing Fan
Keyword(s):  
Mass Flow ◽  
Cross Sections ◽  
Lateral Wall ◽  
Physical Parameters ◽  
Height Ratio ◽  
Dsmc Method ◽  
Flow Rates ◽  
Wide Range ◽  
Mass Flow Rates ◽  
Poiseuille Flows

This paper investigates the Poiseuille flows for rectangular, regular hexagonal, and semicircular cross sections in transition regime using particle approaches, namely the direct simulation Monte Carlo (DSMC) method and the information preservation (IP) method. The DSMC and IP results compare well with each other, while the IP method is much more computationally efficient than the DSMC method. The mass flow rates given by IP and DSMC are in agreement with the BGK solutions of Hasegawa and Sone. For rectangular cross sections in the wide range of the width-to-height ratio, the simulation results of the mass flow rates and the velocity profiles along the midperpendicular line have been given for both methods to estimate the lateral wall influence. For the physical quantities, such as the mass flow rate, which are influenced by the whole field, the lateral wall influence must be considered even for width-to-height ratio as large as 10. And for the physical parameters, such as the maximum velocity and the velocity profile along the midperpendicular line, the lateral wall influence can be negligible if the width-to-height ratio is bigger than 5.

Radiation Hydrodynamics of Accreting Magnetic White Dwarfs

1996 ◽  
Vol 158 ◽  
pp. 199-202 ◽  
Author(s):  
K. Beuermann ◽  
U. Woelk
Keyword(s):  
Mass Flow ◽  
White Dwarfs ◽  
Radiation Hydrodynamics ◽  
Hydrodynamic Equations ◽  
Flow Rates ◽  
One Dimensional ◽  
Cyclotron Radiation ◽  
Wide Range ◽  
Mass Flow Rates ◽  
Two Fluid

AbstractWe solved the stationary one-dimensional two-fluid radiation hydrodynamic equations including cyclotron radiation for a wide range of mass flow rates. Here, we discuss the implications for accretion phenomena on the white dwarfs in AM Her binaries.

Validation of a Coupled Fluid/Solid Heat Transfer Method

2011 ◽  
Author(s):  
Jose M. Chaquet ◽  
Roque Corral ◽  
Guillermo Pastor ◽  
Jesus Pueblas ◽  
D. D. Coren
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mass Flow ◽  
Flow Rates ◽  
Coupled Method ◽  
Mass Flow Rates ◽  
Transfer Method ◽  
Steady Heat ◽  
Fully Coupled

A coupled method for solid/fluid steady heat transfer calculations is presented. The results of the fully coupled and uncoupled simulations are compared with the experimental data obtained for the front and rear stator well of a turbine. Several cooling mass flow rates have been considered. The uncoupled methodology is described as well and the accuracy of the results for both approaches is discussed. It is concluded that even if the uncoupled approach it is conducted carefully, the coupled method is more accurate since it removes some hypotheses inherent to the uncoupled approach.

Numerical Study of Aerodynamic Losses of Effusion Cooling Holes in Aero-Engine Combustor Liners

2010 ◽  
Author(s):  
A. Andreini ◽  
A. Bonini ◽  
G. Caciolli ◽  
B. Facchini ◽  
S. Taddei
Keyword(s):  
Mass Flow ◽  
Cooling System ◽  
Numerical Study ◽  
Data Set ◽  
Flow Rates ◽  
Discharge Coefficients ◽  
Wide Range ◽  
Depth Analysis ◽  
Aero Engine ◽  
Mass Flow Rates

Due to the stringent cooling requirements of novel aeroengines combustor liners, a comprehensive understanding of the phenomena concerning the interaction of hot gases with typical coolant jets plays a major role in the design of efficient cooling systems. In this work an aerodynamic analysis of the effusion cooling system of an aero-engine combustor liner was performed; the aim was the definition of a correlation for the discharge coefficient (CD) of the single effusion hole. The data was taken from a set of CFD RANS simulations, in which the behavior of the effusion cooling system was investigated over a wide range of thermo fluid-dynamics conditions. In some of these tests, the influence on the effusion flow of an additional air bleeding port was taken in account, making possible to analyze its effects on effusion holes CD. An in depth analysis of the numerical data set has pointed out the opportunity of an efficient reduction through the ratio of the annulus and the hole Reynolds numbers: the dependence of the discharge coefficients from this parameter is roughly linear. The correlation was included in an in-house one dimensional thermo-fluid network solver and its results were compared with CFD data. An overall good agreement of pressure and mass flow rates distributions was observed. The main source of inaccuracy was observed in the case of relevant air bleed mass flow rates, due to the inherent three-dimensional behavior of the flow close to bleed opening. An additional comparison with experimental data was performed in order to improve the confidence in the accuracy of the correlation: within the validity range of pressure ratio in which the correlation is defined (> 1.02), this comparison pointed out a good reliability in the prediction of discharge coefficients. An approach to model air bleeding was then proposed, with the assessment of its impact on liner wall temperature prediction.

Numerical Modeling of Pressure Drop and Pump Design for High Power Density Microchannel Heat Sinks With Boiling

2005 ◽  
Author(s):  
Yun Whan Na ◽  
J. N. Chung ◽  
Fred Forster
Keyword(s):  
Experimental Data ◽  
Mass Flow ◽  
Current Model ◽  
Scale Model ◽  
Working Fluid ◽  
Heat Flow Rate ◽  
Pump Design ◽  
Flow Rates ◽  
Macro Scale ◽  
Mass Flow Rates

A physical and mathematical model has been developed to predict the two-phase flow and heat transfer in a microchannel with boiling. Based on the above physical model, a total of seven unknowns with corresponding equations resulted. The liquid film thickness, the vapor pressure and the axial heat flow rate have been solved using a fourth-order Runge-Kutta method. The liquid pressure, the vapor and liquid temperatures have been solved using the finite difference method with first order accuracy. The interfacial temperature and pressure have been solved using the root finding method for every mesh point in the axial direction. In addition to the sample calculations that were used to calibrate the model, computations based on the current model were performed to generate results for comparison with Carey’s macro-scale model (Carey, 1992) and with the experimental data of Jiang et al. (2002) where three different mass flow rates of the working fluid were used in the experiment. The comparisons of pressure drops were made for 25 W, 38 W and 58 W of heating with mass flow rates of 2 ml/min, 5 ml/min and 9ml/min, respectively. In general, Carey’s model underpredicted the experimental data by Jiang et al. (2002), especially at the lower flow rates. The calculated results from the current model matched closely with those of Jiang et al. (2002). The main reason for the poor performance of Carey’s model is that it was developed for the macrosystems, where the surface tension and the Marangoni effects are not important.

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