Pressure Flow Rate Relationship Research Articles

Pressure-Drop Oscillations in a Horizontal Single Boiling Channel

The dynamic behavior of a horizontal boiling channel with a surge tank is investigated through a nonlinear analysis. The surge tank is subject to a constant inlet flow rate and the outlet pressure-flow rate relation of the downstream boiling regime is described by a constitutive model containing a cubic nonlinearity. Within certain operating regimes, the model exhibits self-excited periodic oscillations which can be identified with pressure-drop oscillations. In this study, these oscillations are described as relaxation oscillation and the qualitative features of the response can be understood in terms of the underlying model. Finally, the present model is compared with the experimental data available in literature.

Investigation of the Dynamic Behavior of a Collapsible-Tube Model Through Nonlinear Analysis

In this paper, the dynamic behavior of a collapsible-tube system consisting of a reservoir with inlet and outlet flow conditions is investigated using nonlinear analysis approach. The reservoir is subject to a constant inlet flow rate and the outlet flow rate and the pressure–flow rate relation of the downstream collapsible regime is presented by a constitutive model containing a cubic nonlinearity. Within certain operating regimes, the model exhibits self-excited time-periodic oscillations, which can be identified with pressure-drop oscillations. These oscillations are rationalized to be relaxation oscillations and the qualitative features of the response including the limit cycle and the mechanisms are discussed based on numerical results.

Performance of a Viscous Pump with Radial Pumping Grooves at Low Speeds

A disk-type viscous pump with radial pumping grooves on its stator has been shown to have a linear pressure-flow rate relationship. However, as recently reported, at high rotor speeds (ranging from 600 to 1800 rpm), its pressure-flow rate relations are no longer linear due to the increase of the working fluid temperature during its operation. For this reason, a prototype of such a pump has been tested at relatively low rotor speeds ranging from 50 to 500 rpm. Comparisons between the experimental results and the analytical predictions show very good agreement, especially for the lower rotor speeds which confirm the linearity and accuracy of the derived pressure-flow rate relation.

Performance of a Viscous Pump with Radial Pumping Grooves

A disk-type viscous pump with radial pumping grooves on its stator has been previously shown to have linear pressure-flow rate relationships. However, the gradual increase of the working fluid temperature in practice makes the pressure-flow rate relations no longer linear. For this reason, a prototype of such a pump has been retested for rotor speeds ranging from 600 to 1800 rpm, and a few methods for comparing the test data with the analytical predictions have been suggested. The comparisons show very good agreement for all the rotor speeds tested.

高精度測定用ニッケルメッシュフィルターＳＣＦ‐ＮＭ‐□型

“SOKKEN” Model SCF-NM-_??_s, nicke mesh filters, are porous thin metal membranes produced by a combined technology of photo-resist processing and highly advanced nickel plating, manufactured by Dainippon Printing and standardized by Tsukasa Sokken. We specified that the filter should have a diameter of 13mm, a thickness of 11μm, pore diameters of 2.9 to 5.4μm, the inter-pore distance of 35μm, and a pore number of about 55, 600. We determined the effective pore diameter of the filters with an accuracy of the order of 0.01μm, using pressure-flow rate relationships of airflow.

An empirical model of hydrocyclones incorporating angle of cyclone inclination

Experimental work has been undertaken to quantify the influence of angle of inclination on hydrocyclone performance in mineral processing applications. Testwork was undertaken at Mount Isa Mine on copper and lead-zinc slurries and in the JKMRC laboratory on a gold ore and other ores. In both cases the cyclone performance was monitored at a range of cyclone inclinations from zero to 112°C to the vertical. Cyclone diameter varied from 102 to 508mm. The results show that cyclone inclinations greater than 45° can strongly affect the performance of industrial cyclones. A new empirical model of classifying hydrocyclone performance has been developed on the basis of this data, incorporating angle of inclination and slurry viscosity as variables, and including prediction of cut-size, separation quality, water recovery and the pressure-flowrate relationship.

Particulate Suspension Flow Induced by Sinusoidal Peristaltic Waves

The flow of a particle-fluid suspension induced by simusoidal peristaltic waves in an axisymmetric tube and in a two-dimensional channel under long wavelength approximation, is studied. The equations governing the flow for both the fluid and particle phase are solved and the expressions for the dimensionless flow rate, pressure drop and friction force are derived. The results obtained are discussed briefly and compared with other studies to observe the effect of particle concentration in the fluid. It is shown that pressure drop decreases with flow rate and its minimal is achieved at zero flow rate. Pressure drop increases with particle concentration but decreases with increasing amplitude ratio. Pressure-flow rate relationships are found to be linear for any given set of parameters. Friction force posseses a similar character to pressure drop and qualitatively the results of two-dimensional geometry is similar to axisymmetric case. Besides its applications to wide range of engineering and biological problems, it is hoped that the axisymmetric tube analysis may be used to study the two-phase peristaltic induced flow of blood.

Experimental Study of a Disk-Type Viscous Pump with Radial Pumping Grooves

Abstract A prototype of a new disk-type viscous pump with radial pumping grooves on its stator (as previously reported) has been successfully fabricated and experimentally tested for rotor speeds of 600, 900, 1200, 1500, and 1800 rpm, at a nominal rotor-stator gap of 133 μm. The test results of each speed reveal gradual increase in the working fluid temperature which makes its pressure-flow rate relationships no longer linear in practice. This can be the main practical problem in operating such a pump, and for this reason, a few methods of comparison between the test results and the analytical predictions have been proposed. By minimizing the time taken for data collection, the test results obtained agree very well with the analytical predictions for all the speeds tested. This experimental study has also demonstrated that this new disk-type viscous pump is practically feasible.

F47. Rheologic characterization of nickel mesh filter by pressure-flow rate relationships in airflow

F47. Rheologic characterization of nickel mesh filter by pressure-flow rate relationships in airflow

特集：血液細胞の細胞膜の研究における最近の進歩 赤血球のレオロジー 赤血球の変形と膜骨格を考慮して

In order to understand quantitatively both the macroscopic and the microscopic behavior of blood, we have attempted to review three main areas of red blood cell (RBC) rheology based on our recent work : 1) the macroscopic flow behavior of RBCs, i. e., viscosity and pressure-flow rate relationships of RBC suspension; 2) the microrheological behavior of RBCs, i. e., RBC deformability; 3) a role of membrane cytoskeleton in microrheological properties of RBCs. Especially, we presented a new quantitative filtration method using a newly developed thin metal film with pores (the nickel mesh), and demonstrated a close link between decreased deformability of RBCs and fragmentation of membrane cytoskeletal proteins including a role of hemoglobin in it. Although the present review is limited in both breadth and depth, it may contribute to provide a new insight into RBC rheology.

Analysis of Modified Isochronal Tests To Predict The Stabilized Deliverability Potential of Gas Wells Without Using Stabilized Flow Data (includes associated papers 12933, 16320 and 16391 )

Two new methods (simplified isochronal test [SIT] analyses) to predict thestabilized deliverability potential of gas wells are presented. Thesetechniques use isochronal data from modified isochronal tests and alsoprovide reasonable values of permeability-thickness (kh), skin factor (s), provide reasonable values of permeability-thickness (kh), skin factor (s), and inertial-turbulent flow factor (D). Introduction The most commonly used method to predict the initialstabilized deliverability potential of a gas well is themodified isochronal test that includes an extended flowperiod to pressure stabilization. Some reservoirs do not period to pressure stabilization. Some reservoirs do not attain stabilization even after 100 or more hours of nowand consequently a reliable, extended flow period onsuch reservoirs can be unreasonably expensive andwasteful. In many instances, new wells are not tied into apipeline before testing, in which cases gas must be flared pipeline before testing, in which cases gas must be flared during a test. Regulatory agencies such as the AlbertaEnergy Resources Conservation Board (AERCB) haveimposed limitations (20 MMscf) on the amount of gasthat can be flared during most gas well tests. Tocircumvent this problem, the isochronal portion of a test may beconducted while the extended flow period is delayed untilthe well is tied into a pipeline. Finally, in many caseswhere complete, modified iochronal test have beenrun, extended flow tests simply are not conducted tostabilization and the stabilized deliverability potentialmust be estimated from just the isochronal flow data. This paper presents two simple techniques to predictthe stabilized deliverability potential, using only theisochronal data from modified isochronal tests. With eitherof the proposed techniques, which are referred to as"simplified isochronal test (SIT) analyses," it ispossible to obtain reasonable values of permeability-thickness possible to obtain reasonable values of permeability-thickness (kh), skin factor (s), and inertial-turbulent flow factor(D). These reservoir parameters may be used with otherwell and reservoir data to predict the stabilizeddeliverability potential of gas wells. These techniques are based on existing theory for theanalysis of gas well-test data. The quadratic form of thedeliverability equation describes the pressure-flow raterelationship. The transient and stabilized flowcoefficients in this equation are calculated using SIT methods. The isochronal-test method described by Cullenderand the modified isochronal-test method proposed byKatz et al. have been used extensively to developperformance curves for gas wells-particularly the performance curves for gas wells-particularly the modified isochronal tests. A requirement of such testingprocedures is a flow period to pressure stabilization, procedures is a flow period to pressure stabilization, or stabilized flow. This requirement is not found often, particularly in low-permeability reservoirs. Even in particularly in low-permeability reservoirs. Even in reservoirs with good producing characteristics and faststabilization, it is undesirable from a conservation standpointto flare gas needed to establish stabilized flow. Consequently, the supposedly stabilized deliverabilitypotential reported in tests usually is not representative of potential reported in tests usually is not representative of the stabilized performance of wells. The methodspresented here overcome this deficiency and are valuable in presented here overcome this deficiency and are valuable in certain situations where it is impossible to conduct astabilized flow test. JPT P. 297