Investigation of Plateau Border Profile Shape with Flow of Surfactant Solution through Foam under Constant Pressure Drop Using the FPDT Method

2014 ◽  
pp. 109-125
Author(s):  
Pyotr M. Kruglyakov ◽  
Natalia G. Vilkova
Keyword(s):  
Pressure Drop ◽  
Constant Pressure ◽  
Surfactant Solution ◽  
Plateau Border ◽  
Profile Shape

Steam-foam performance in oil sand cores at constant pressure drop

Fuel ◽  
1991 ◽  
Vol 70 (11) ◽  
pp. 1303-1307 ◽  
Author(s):  
M.Kirk Green ◽  
E.Eddy Isaacs ◽  
John M. Smid
Keyword(s):  
Pressure Drop ◽  
Constant Pressure ◽  
Oil Sand

HYDRODYNAMIC CALCULATION OF CONTACTLESS SEALS WITH PLANE SLOTS IN DRIVES OF ELECTRIC POWER SYSTEMS

2021 ◽  
Vol 11 (2) ◽  
pp. 171-177
Author(s):  
Evgeny A. KRESTIN ◽  
Grigoriy V. SEREBRYAKOV
Keyword(s):  
Pressure Drop ◽  
Power Systems ◽  
Electric Power ◽  
Constant Pressure ◽  
Saturated Vapor ◽  
Electric Power Systems ◽  
Navier Stokes ◽  
Friction Forces ◽  
Continuity Equations ◽  
Special Cases

Non-contact seals with fl at slott ed gaps of drives of electric power systems used in switchgears of hydraulic units, as well as in pumps and hydraulic motors have been investigated. Calculation of seals based on average clearance results in an underestimation or overestimation of the leakage rate compared to the operational values. The regularity of the distribution of pressure and fl ow rate in the gap of a fl at conical slot is determined, and formulas for the fl ow rate (leakage) and friction forces acting on the walls of the conical slot are found. To solve the problem, the approximate Navier-Stokes and fl ow continuity equations are used. Several special cases of the fl ow of the working fl uid in diff erent gaps are considered: a plane-parallel gap with an oscillating wall and at a constant pressure gradient and a conical gap at diff erent ratios of the pressure drop and the frictional action of the moving channel wall. When the wall oscillates in a conical gap and constant pressure, the presence of an extremum is characteristic. In this case, an excess pressure appeared in the slott ed gap, creating a supporting force, and the pressure value became high enough. When the lower wall of the conical slot moves in the direction of the increasing gap, the pressure inside the slott ed channel, under certain conditions, can reach a complete vacuum, the value of which is limited by the bulk strength of the liquid and the pressure of saturated vapor at a given temperature. When the pressure drop and oscillations of the wall of the conical gap are additive, then at a suffi ciently high velocity of the wall movement, the pressure inside the slot can even increase and exceed the value of the supplied pressure.

Analysis and Optimization Design of Pressure Compensated Flow Control Valves

2003 ◽  
Author(s):  
Duqiang Wu ◽  
Richard Burton ◽  
Greg Schoenau ◽  
Doug Bitner
Keyword(s):  
Pressure Drop ◽  
Flow Control ◽  
Flow Rate ◽  
Total Pressure ◽  
Optimization Design ◽  
Constant Pressure ◽  
Control Device ◽  
Operating Conditions ◽  
Flow Control Device ◽  
Linearized Model

A pressure compensated valve (PC valve) is a type of flow control device that is a combination of a control orifice and a compensator (often called a hydrostat). The compensator orifice modulates its opening to maintain a constant pressure drop across the control orifice. In other words, the PC valve is so designed that the flow rate through the valve is governed only by the opening of the control orifice and is independent of the total pressure drop across the valve. Because of the high non-linearities associated with this type of valve, it is impossible, in practice, to design such a valve where the flow rate is completely unaffected by the pressure drop across the valve. In this paper, the effect of the non-linerities on the performance of the PC valve is investigated. First, a generic non-liner model of a PC valve is developed. Using this model, all possible operating conditions can be determined. Then a linearized model is developed and used to analyze the dynamic behavior of the PC valve. The model can then be used to optimize the design and operation of the valve for specific applications.

On elastic regime of filtration in hydraulic fracture

2016 ◽  
Vol 11 (2) ◽  
pp. 156-166
Author(s):  
V.Sh. Shagapov ◽  
Z.M. Nagaeva
Keyword(s):  
Pressure Drop ◽  
Rheological Properties ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Hydraulic Fracture ◽  
Constant Pressure ◽  
Constant Flow ◽  
Exact Analytical Solutions ◽  
Constant Flow Rate ◽  
Pressure Evolution

Fluid recovery from a well in the modes of constant pressure drop and constant flow rate is considered basing on a theoretical model of filtration in a hydraulic fracture. Exact analytical solutions are obtained that allowed analyzing the effect of the reservoir and fracture properties (such as porosity, permeability and crack width) as well as the rheological properties of the saturating fluid upon: pressure evolution in the fracture, well flow rate at constant pressure drop, and pressure evolution in the wellbore. On the basis of theoretical models describing the filtration for a crack in an oil or gas reservoirs, the considered problem on the selection of fluids from the well in modes constant differential pressure and constant flow. For the considered tasks are received exact analytical solutions, based on which we analyzed the influence of reservoir characteristics of the formation and fractures (for example, their porosity, permeability and width of cracks) and the rheological properties of the saturating fluid on the evolution of the pressure in the fracture, the production rate at a constant differential to the dynamics of the pressure in the well.

Experimental Investigation of the Effect of Surface Tension and the Correlation on Void Fraction and Frictional Pressure Drop of an Air-Liquid Two-Phase Flow in a Horizontal Flat Capillary Rectangular Channel

2003 ◽  
Author(s):  
Hideo Ide ◽  
Tohru Fukano
Keyword(s):  
Surface Tension ◽  
Pressure Drop ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Surfactant Solution ◽  
Phase Flow ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Effect Of Surface

Air-liquid two-phase flow in a horizontal flat capillary rectangular channel has been studied to clarify the effects of concentration of surfactant solution on the flow phenomena, such as flow patterns, pressure drop, void fraction and so on. The concentrations of surfactant solution were 0, 10, 50 and 100 ppm and the surface tension of each solution was reduced to about 34mN/m from that of pure water of about 72mN/m. The dimension of the channel used was 10.0 mm × 1.0 mm. The drag reduction by mixing the surfactant was examined in both the single phase flow and the two-phase flow. The experimental data of two-phase frictional pressure drop and holdup were compared with the respective correlations which were previously proposed by the other researchers and the present authors. Finally, we proposed new correlations of two-phase frictional pressure drop and holdup in which the effect of surface tension and the aspect ratio of cross section of channel were taken into account.

scholarly journals Effects of Pressure Drops on the Performance Characteristics of Air Standard Otto Cycle

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Mahmoud Huleihil
Keyword(s):  
Pressure Drop ◽  
Constant Pressure ◽  
Performance Characteristics ◽  
Maximum Efficiency ◽  
Maximum Pressure ◽  
Otto Cycle ◽  
Pressure Drops ◽  
Internal Irreversibility ◽  
Expansion Model ◽  
Engine Size

The effects of pressure drops on the performance characteristics of the air standard Otto cycle are reported. The pressure drops are assumed as constant values independent of the engine size. It has been shown that the pressure drops to about 60% of the maximum pressure in the ideal cycle (Curto-Risso et al., 2008). Three different models are studied: constant pressure model, reversible adiabatic expansion model and polytropic expansion model. The findings of this study show that, at this level of pressure drop, the maximum efficiency of the Otto cycle is reduced by 15% approximately based on the constant pressure model. The combined effect of pressure drop with other modes of irreversibility, for example, internal irreversibility and heat leaks, could reduce the maximum efficiency into very low values (approximately 30%). The reversible adiabatic model predicts reduction of 13% in efficiency at 40% pressure drop levels but at the price of zero power production. On the other hand, the polytropic expansion model predicts 40% reduction in efficiency for the same level of pressure drop (40%). All three models show that the power output is very sensitive to pressure drop.

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