Hydrodynamic characteristic of Conical Cap tray: Experimental studies on dry and total pressure drop, weeping and entrainment

2013 ◽  
Vol 64 ◽  
pp. 17-23 ◽  
Author(s):  
Taleb Zarei ◽  
Rahbar Rahimi ◽  
Ali Zarei ◽  
Mortaza Zivdar
Keyword(s):  
Pressure Drop ◽  
Total Pressure ◽  
Experimental Studies ◽  
Hydrodynamic Characteristic ◽  
Total Pressure Drop

scholarly journals Optimal Design and Performance Analysis of Radial MR Valve with Single Excitation Coil

Actuators ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 34
Author(s):  
Guoliang Hu ◽  
Feng Zhou ◽  
Lifan Yu
Keyword(s):  
Pressure Drop ◽  
Magnetic Flux ◽  
Internal Structure ◽  
Total Pressure ◽  
Damping Force ◽  
Flux Lines ◽  
Total Pressure Drop ◽  
Excitation Coil ◽  
Static Performance ◽  
And Performance

The main issue addressed in this paper involves the magnetorheological (MR) valve increasing the pressure drop by changing the internal structure, which leads to the increase of dimension sizes and the easy blocking of the internal channel. Optimizing the design of the traditional radial MR valve without changing the internal structure and whole dimension size is indispensable. Firstly, a radial MR valve with single excitation coil was proposed. The mathematical models of the field-dependent pressure drop and viscosity pressure drop in fluid flow channels were deduced, and the calculation formula of pressure drop was also established. Then, ANSYS software was used to simulate and analyze the distributions of the magnetic flux lines and magnetic flux densities of the proposed radial MR valve. Subsequently, the radial MR valve was simulated and analyzed by using the ANSYS first-order and zero-order simulation tools. In addition, the experimental test bench of the proposed MR valve was setup, the static performance of pressure drop was tested, and the change of pressure drop of the optimal radial MR valve under different loads was studied, furthermore, the response time with current of the initial and optimal radial MR valve were also investigated. Finally, the dynamic performances of the optimal radial MR valve controlled cylinder system under different currents, frequencies and amplitudes were tested, respectively. The experimental results indicate that the total pressure drop of the initial valve is 1.842 MPa when the applied current is 1.8 A, and the total pressure drop of the optimal valve is 2.58 MPa, the increase is 40.07%. Meanwhile, the maximum damping force of the optimal radial MR valve controlled cylinder system can reach about 3.6 kN at the current of 1.25 A, which shows a better optimization effect of the optimal radial MR valve.

Estimation of Filtering Velocity and Pressure Drop Parameters from Total Pressure Drop in a Multi-Compartment Bag Filter

2003 ◽  
Vol 29 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Hidenori Ikeno ◽  
Yutaka Tada ◽  
Setsuro Hiraoka ◽  
Yusuke Shuto
Keyword(s):  
Pressure Drop ◽  
Total Pressure ◽  
Bag Filter ◽  
Total Pressure Drop

Genetic Algorithm Optimization for Primary Surfaces Recuperator of Microturbine

2006 ◽  
Vol 129 (2) ◽  
pp. 436-442 ◽  
Author(s):  
Wang Qiuwang ◽  
Liang Hongxia ◽  
Xie Gongnan ◽  
Zeng Min ◽  
Luo Laiqin ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Pressure Drop ◽  
Total Pressure ◽  
Superior Performance ◽  
Operating Pressure ◽  
Minimum Volume ◽  
Original Design ◽  
Design Data ◽  
Total Pressure Drop ◽  
Geometry Characteristic

In recent years, the genetic algorithm (GA) technique has gotten much attention in solving real-world problems. This technique has a strong ability for global searching and optimization based on various objectives for their optimal parameters. The technique may be applied to complicated heat exchangers and is particularly useful for new types. It is important to optimize the heat exchanger, for minimum volume/weight, to save fabrication cost or for improved effectiveness to save energy consumption, under the requirement of allowable pressure drop; simultaneously it is mandatory to optimize geometry parameters of heating plate from technical and economic standpoints. In this paper, GA is used to optimize the cross wavy primary surface (CWPS) and cross corrugated primary surface (CCPS) geometry characteristic of recuperator in a 100kW microturbine, in order to get more compactness and minimum volume and weight. Two kinds of fitness assignment methods are considered. Furthermore, GA parameters are set optimally to yield smoother and faster fitness convergence. The comparison shows the superiority of GA and confirms its potential to solve the objective problem. When the rectangular recuperator core size and corrugated geometries are evaluated, in the CWPS the weight of the recuperator decreases by 12% or more; the coefficient of compactness increases by up to 19%, with an increase of total pressure drop by 0.84% compared to the original design data; and the total pressure drop versus the operating pressure is controlled to be less than 3%. In the CCPS area compactness is increased to 70% of the initial data by decreasing pitch and relatively high height of the passage, the weight decreases by 17–36%, depending on the inclination angle (θ). Comparatively the CCPS shows superior performance for use in compact recuperators in the future. The GA technique chooses from a variety of geometry characters, optimizes them and picks out the one which provides the closest fit to the recuperator for microturbine.

The Effect of Crossflow on Waterflooding of Stratified Reservoirs (includes associated papers 14490 and 14692 and 15043 and 15191 )

1985 ◽  
Vol 25 (02) ◽  
pp. 291-302 ◽  
Author(s):  
Noaman El-Khatib
Keyword(s):  
Pressure Drop ◽  
Oil Recovery ◽  
Reservoir Simulation ◽  
Total Pressure ◽  
Vertical Direction ◽  
Depositional Environments ◽  
Mobility Ratio ◽  
Fluid Saturation ◽  
Total Pressure Drop ◽  
Log Normal

Abstract A mathematical model is developed for waterfloodingperformance in linear stratified systems for both cases of noncommunicating layers with no crossflow and communicating layers with complete crossflow. The model accounts for variation of porosity and saturation inaddition to permeability of the different layers. The modelpredicts the fractional oil recovery, the water cut, the totalvolume injected, and the change in the total pressure drop, or the change in injection rate at the water breakthroughin the successive layers. A systematic procedure forordering of layers and performing calculations is outlined. Aprocedure for combining layers to avoid instability in the case of low mobility ratio is introduced. The developed model is applied to different examplesof stratified reservoirs. The effects of mobility ratio and crossflow between layers are discussed. The effects of variable porosity and fluid saturation are discussed also. It was found that crossflow between layers enhancesthe oil recovery for systems with favorable mobility ratios(lambda w/lambda o less than 1) and retards oil recovery for systems with unfavorable mobility ratios. It was found also that crossflow causes the effect of the mobility ratio on oil recovery to become more pronounced. The variation of porosity andfluid saturation with permeability is found to increase oilrecovery over that for the case of uniform porosity andsaturation for both favorable and unfavorable mobility ratios. Introduction Because of the variation in the depositional environments, oil-bearing formations usually exhibit random variationsin their petrophysical properties in both horizontal and vertical directions. Statistical as well as geological criteria usually are used to divide the pay zone betweenadjacent wells into a number of horizontal layers each with its own properties (k, phi, h, Swi, and Sor). Suchreservoirs usually are called "stratified," "layered,"or"heterogeneous" reservoirs. This variation in properties affects the performance of oil reservoirs during primary and secondary recovery processes. One of the significant factors influencingrecovery performance during waterflooding is thevariation of permeability in the vertical direction. In this case, the displacing fluid (water) tends to move faster in zones with higher permeabilities, causing earlier breakthrough of water into the producing wells and eventual by passing of some of the displaced fluid (oil). The various methods used for the prediction of waterflooding performance of stratified reservoirs differin the way the communication between the different layersis treated. Two ideal cases usually are used:completely noncommunicating layers andcommunicating layerswith complete crossflow. For actual stratified Systems, however, the layers are partially connected in the vertical direction, and the performance of the system lies betweenthose of the two ideal cases. For the case of noncommunicating stratified layers, the methods of Stiles and Dykstra-Parsons usually areused. Stiles' method assumes unit mobility ratio for the displacement process when computing the recovery but accounts for the mobility ratio when computing the WOR, which results in contradictory formulas for the performance. The Dykstra-Parsons method and its modified version by Johnson use semiempirical correlations based on log-normal distribution of the layers' permeability. Muskat presented analytical expressions for the performance of reservoirs having linear and exponential permeability distributions. Two methods are available in the literature forestimating the performance of communicating systems with complete crossflow the method of Warren and Cosgrove and that of Hearn. Warren and Cosgrove's method requires a log-normal permeability distribution. Furthermore, it ignores the problem of ordering of layersfor low mobility ratio, which may cause physicallymeaningless results. The method of Hearn is intended to derive pseudorelative permeability functions for the stratified system to be used in reservoir simulation. Most of these methods assume that all layers have identical properties except permeability. Also, the time is notrelated explicitly to the performance. Furthermore, noneof these methods considers the variation in injection rateand total pressure drop as the displacement process progresses. Although these points can be treated numerically for a particular case using reservoir simulation methods, the objective of this work is to developan alytical expressions for waterflooding performance inidealized linear stratified systems that will consider the previously mentioned points. Theoretical Analysis Assumption and Definitions. For both the noncommunicating and communicating systems, these assumptions are made. 1. The system is linear and horizontal, and the flow is incompressible, isothermal, and obeys Darcy's law. SPEJ P. 291^

Thermal Design of Heat Exchanger With Fins Inside and Outside Tubes

2006 ◽  
Author(s):  
G. N. Xie ◽  
Q. Y. Chen ◽  
M. Zeng ◽  
Q. W. Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Total Pressure ◽  
Thermal Design ◽  
Operating Pressure ◽  
Heat Transfer Area ◽  
Tube Heat Exchanger ◽  
Total Pressure Drop

Compact heat exchangers such as tube-fin types and plate-fin types are widely used for gas-liquid or gas-gas applications. Some examples are air-coolers, fan coils, regenerators and recuperators in micro-turbines. In this study, thermal design of fin-and-tube (tube-fin) heat exchanger performance with fins being employed outside and inside tubes was presented, with which designed plate-fin heat exchanger was compared. These designs were performed under identical mass flow rate, inlet temperature and operating pressure on each side for recuperator in 100kW microturbine as well as specified allowable fractions of total pressure drop by means of Log-Mean Temperature Difference (LMTD) method. Heat transfer areas, volumes and weights of designed heat exchangers were evaluated. It is shown that, under identical heat duty, fin-and-tube heat exchanger requires 1.8 times larger heat transfer area outside tubes and volume, 0.6 times smaller heat transfer area inside tubes than plate-fin heat exchanger. Under identical total pressure drop, fin-and-tube heat exchanger requires about 5 times larger volume and heat transfer area in gas-side, 1.6 times larger heat transfer area in air-side than plate-fin heat exchanger. Total weight of fin-and-tube heat exchanger is about 2.7 times higher than plate-fin heat exchanger, however, the heat transfer rate of fin-and-tube heat exchanger is about 1.4 times larger than that of plate-fin heat exchanger. It is indicated that, both-sides finned tube heat exchanger may be used in engineering application where the total pressure drop is severe to a small fraction and the operating pressure is high, and may be adopted for recuperator in microturbine.

Developing Region Solution for High Reynolds Number Laminar Flows of Pseudoplastic and Dilatant Fluids in Circular Ducts

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Massimo Capobianchi ◽  
Patrick McGah
Keyword(s):  
Shear Rate ◽  
Pressure Drop ◽  
Power Law ◽  
Total Pressure ◽  
Correlation Equation ◽  
Laminar Flows ◽  
Graphical Form ◽  
Shear Rates ◽  
Total Pressure Drop ◽  
High Reynolds

This article reports the results of a numerical computation of the length and total pressure drop in the entrance region of a circular tube with laminar flows of pseudoplastic and dilatant fluids at high Reynolds numbers (i.e., approximately 400 or higher). The analysis utilizes equations for the apparent viscosity that span the entire shear rate regime, from the zero to the infinite shear rate Newtonian regions, including the power law and the two transition regions. Solutions are thus reported for all shear rates that may exist in the flow field, and a shear rate parameter is identified that quantifies the shear rate region where the system is operating. The entrance lengths and total pressure drops were found to be bound by the Newtonian and power law values, the former being approached when the system is operating in either the zero or the infinite shear rate Newtonian regions. The latter are approached when the shear rates are predominantly in the power law region but only if, in addition, the zero and infinite shear rate Newtonian viscosities differ sufficiently, by approximately four orders of magnitude or more. For all other cases, namely, when more modest differences in the limiting Newtonian viscosities exist, or when the system is operating in the low- or high-shear rate transition regions, then intermediate results are obtained. Entrance length and total pressure drop values are provided in both graphical form, and in tabular and correlation equation form, for convenient access.

Flow With Losses

1965 ◽  
Vol 87 (1) ◽  
pp. 37-49
Author(s):  
R. P. Benedict ◽  
N. A. Carlucci
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Total Pressure ◽  
Constant Density ◽  
Trial And Error ◽  
Exact Analytical Solutions ◽  
Total Pressure Drop ◽  
Loss Coefficients ◽  
Iterative Procedures

Even when one is willing to estimate the various loss coefficients in a given system, it is not always an easy matter to determine the flow rate and/or the total pressure drop across the system. Heretofore, a tedious trial-and-error approach (at the least) has been indicated, and this has often been based on a Darcy approximation which is questionable under certain conditions. In this paper we present, for compressible and constant-density flows with losses, the developments of exact, albeit simplified, numerical and graphical solutions which are free from all iterative procedures. Comparisons are drawn between these exact analytical solutions and several Darcy approximations. Sample problems are given to illustrate the graphical and tabular solutions as presented here.

scholarly journals Optimizing Design and Analysis on The Helically Coiled Tube Heat Exchanger By Providing Fins

2020 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Sunil Kumar ◽  
Ravindra Mohan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Total Pressure ◽  
Outlet Temperature ◽  
Tube Heat Exchanger ◽  
Helically Coiled Tube ◽  
Total Pressure Drop ◽  
Optimizing Design ◽  
Coil Heat Exchanger

Heat exchangers are an essential part in an assortment of mechanical settings, for example, cooling frameworks, force plants, refineries, and in this way ceaseless endeavor are made to expand their heat transfer efficiencies. Optimize design of helical coil heat exchanger by using fins and the Compare pressure & temperature by conventional design. The final outcome of the study increase the total heat transfer rate inside the domain. And increase the pressure drop inside the domain. The water outlet temperature decrease up to 315k and cold outlet temperature increase up to 320 k. and total pressure drop increase with the temperature increases. Finally the CFD data were compared with previous data  the total pressure drop increase up to 0.65 bar for case-2.the overall efficiency of the system incites up to 5%  to 6%.

scholarly journals Automated Control Of Aspiration Of Explosion-And Fire-Hazardous Industries With Filters-Dust Collectors

2021 ◽  
Vol 12 (5) ◽  
pp. 1852-1860
Author(s):  
Romanyuk E.V, Et. al.
Keyword(s):  
Experimental Study ◽  
Pressure Drop ◽  
Total Pressure ◽  
Layer Structure ◽  
Pressure Sensors ◽  
Gas Flows ◽  
Automated Control ◽  
Drop Dynamics ◽  
Aspiration System ◽  
Total Pressure Drop

The article presents a scheme for automated control of an aspiration system equipped with filters-dust collectors for production associated with the circulation of explosive dust- gas flows. As an indicator of the state of the entire aspiration, it is proposed to use the total pressure drop on the filter partition and the temperature shown by the pressure sensors. Based on the experimental study of the unrelated layer structure filter total pressure drop dynamics a mathematical description, algorithm and software for trouble-free operation of aspiration were obtained.

Influence of Liquid Viscosity on the Pressure Loss and the Effectiveness of Drag-Reducing Agents in Horizontal Slug Flow

2005 ◽  
Vol 127 (2) ◽  
pp. 149-152 ◽  
Author(s):  
Mutaz Daas ◽  
Derek Bleyle
Keyword(s):  
Pressure Drop ◽  
Slug Flow ◽  
Pressure Loss ◽  
Total Pressure ◽  
Volume Fraction ◽  
Liquid Velocity ◽  
Reducing Agents ◽  
Liquid Volume ◽  
Oil Viscosity ◽  
Total Pressure Drop

Measurements of drag reduction in two-phase oil-gas slug flow are presented in this study. Two types of oil with markedly different viscosities were examined in 10-cm inner diameter horizontal pipes to evaluate the influence of oil viscosity on the total pressure loss and the effectiveness of drag-reducing agents (DRAs) in reducing the pressure drop in slug flow. The total pressure drop in the 50-cP oil was always more significant than in the 2.5-cP oil, especially when increasing the gas flow rate. However, the DRA was more effective in reducing the total pressure drop in the 2.5-cP oil. Furthermore, increasing liquid velocity, thus increasing liquid volume fraction, resulted in an increase in the DRA effectiveness for both oils.

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