Jan 06, 2011 the ejector nozzle flowfield was solved on an unstructured grid using the unstructured grid solver in windus 3. The convergent parts of the nozzle are sharp and frictionless. The input and output files and comparisons of the velocity and total temperature profiles can be found on the unstructured ejector nozzle page. Development and performance of an advanced ejector cooling. The ejector nozzle flowfield was solved on an unstructured grid using the unstructured grid solver in windus 3. Comparison of predicted and experimental wall temperatures. Ejector modeling and examining of possibility of replacing. Internal performance of several types of jetexit configurations for. Variable area jet nozzle for noise reduction using shape. Variable area nozzles are used for adjusting the exit area for different. The gains obtained by ejectors and by corrugated nozzles are to a certain extent additive in that a combination of a corrugated or multiple nozzle and an ejector reduce the aerodynamic noise of a jet still further. Theoretical and experimental study on solar ejector cooling system using r236fa theoretical and experimental study on solar ejector cooling system using r236fa. The experiments indicated that energy saved was raised to 112% by the. Based on the ejector model, there is an optimal nozzle position of 6 mm for a given operating conditions and fixed geometries of this designed ejector, which contributes the highest entrainment.
A shock wave occurs in the diffuser throat when the compression ratio of an ejector is 2. Experimental results with a variable geometry ejector using. Cfd study of a variable area ratio ejector using r600a and. In order to overcome this problem, an advanced ejector was developed that changes its. For this operation condition, the diameter of the motive nozzle throat for the designed ejector was 2. Effects of the nozzle configuration on solarpowered.
Variable flow ejectors are based on proven gea jet pump. Performance characteristics of a variablearea vane nozzle for. Understanding ejector systems necessary to troubleshoot. Preliminary design and computational analysis of an ejector. Ejectors are essentially a fixed capacity device since the diffuser area is constant. Reinstall the carburetor on the engine, if removed, and attach the. Experimental study on a multievaporator refrigeration system. The throat area is usually two to four times larger than the nozzle area. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Experimental observation for multi nozzle liquid jet ejector for chlorineaqueous caustic soda system at laboratory scale k.
Readdressing working fluid selection with a view to designing a variable geometry ejector. Jul 01, 2014 read analysis on performance characteristics of ejector with variable area ratio for multievaporator refrigeration system based on experimental data, applied thermal engineering on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Readdressing working fluid selection with a view to designing. By being supported on and riding with the primary nozzle, when the nozzle is variable, the ejector flap is also variable. A variable area nozzle helps to adjust the exit pressure of the combustion gases to ambient pressure. The definitions of overall ejector efficiency and ejector component efficiencies in literature are. Predicted performance of a thrustenhanced sr71 aircraft. Pdf the benefits of variable area fan nozzles on turbofan. Therefore, they react to control impulses in a manner peculiar to their. While both these areas are fixed in many engines i. A variable ejector for a jet engine having a variable area nozzle, said engine being enclosedby a casing, said ejector comprising a sleeve surrounding the casing of said engine and disposed adjacent the rearward portion thereof.
The model which is developed based on integration equations momentum as well as energy for different parts of ejector, using special. A motive nozzle needle allows precise adaption on varying. When afterburning engines are equipped with a cd nozzle the throat area is variable. A variable area nozzle van on the bypass stream of a turbofan engine may prove to be necessary for a sufficient surge margin on an ultrahigh bypass ratio fan. In the divergent parts, the friction loss may be taken as 0. Based on the designed ejector, effects of motive nozzle throat diameter on performance were studied under conditions of 5 c evaporator temperature and condenser temperature of 40 c.
Expired lifetime application number us102677a inventor frank v purse. The variable area mixing ejector has been developed based on a onedimensional constant rate momentum change gas dynamic theory. Agrawal assistant professor, department of chemical engineering faculty of technology and engineering, the m. If the steam floe rate is 1 kgs and the initial velocity of steam is negligible, find the minimum area of the nozzle. Li and yan 8 carried out an investigation of the variable area ratio ejector on a multi evaporator refrigeration system. Ejector refrigeration is a promising technology for the integration into solar driven cooling systems because of its relative simplicity and low initial cost. Experimental and numerical analysis of a variable area. Research and technology development activities were carried out at the rollsroyce university technology center for high mach propulsion, purdue university. This figure represents the main parts of the ejector such as a nozzle, three types of constantarea sections including discharge and an adjustable spindle of the primary inlet that ranges from 0 fully closed to. The areas of both the propelling nozzle and turbine nozzle set the mass flow through the engine and the maximum pressure. Request pdf analysis on performance characteristics of ejector with variable area ratio for multievaporator refrigeration system based on experimental data this paper presents a study on. The performance of convergingdiverging nozzles with varying length of diverging sections for the ejector refrigeration. This study presents a comprehensive numerical, experimental study and analysis on the effect of nozzle exit position nxp on variable area mixing ejector. The ejectors tested had a constant exit area and variable primary area to provide nozzle area ratios from 1.
Effect of nozzle exit position nxp on variable area. The short ejector fiap added to the primary nozzle offers an easy lightweight solution tothe pumping problem associated with the tertiary inlet nozzle. An ejector performance curve gives the expected suction pressure as a function of. The present experimental study is performed on the basis of an ejector with variable area ratios. Experimental observation for multi nozzle liquid jet ejector. Several researches on convergingdiverging nozzles for the ejector refrigeration cycle were done. When defining certain types of jet ejectors, the standard terms for motive flu. The major drawback of such a system is associated with its relatively low coefficient of performance cop under variable operating conditions. About 5% of these are water treatment, 4% are pumps, and 4% are moulds. This work tries to analyse the performance of a steam ejector working in conjunction with a refrigeration cycle. In an increasing number of applications it is necessary to apply controls. Review on ejector efficiencies in various ejector systems. Hill prepared by dynatech rd company cambridge, mass. Selecting an eductor the venturi is a teeshaped device that passes fluid through a restricting nozzle see figure 9, increasing its flow velocity and.
Readdressing working fluid selection with a view to designing a variable. A theoretical analysis of a variable area ejector is presented. Exhaust nozzles the three exhaust nozzles selected for this program were a cylindrical ejector, an. Primary nozzle the variable area primary exhaust nozzle is made up of overlapping leaves that provide a nearly circular throat. That suction draws chemicals or slurries into the device, mixes it with the feedwater and pushes it downstream. Circuit diagram exe v p vacuum ejector inline type zu series rohs type high vacuum type large flow type model zu05s zu07s zu05l zu07l nozzle diameter mm 0. Determination of efficiency of converging diverging nozzles.
Over expanded and under expanded nozzles, ejector and variable area nozzles, interaction of nozzle flow with adjacent surfaces, thrust reversal. Optimization of a highefficiency jet ejector by computational fluid dynamics software. Theoretical investigation of variable area ejectors carleton. The efficiency of the ejector cycle is very sensitive to the ejector efficiency. Install the new oring on the accelerator pump ejector nozzle picture 7 and the new bowl gasket, included in the kit, on the carb body picture 8, and reinstall the bowl on the carburetor using the screws removed in step 1. Ejector nozzle, ejector nozzle suppliers and manufacturers. In this paper, computational fluid dynamics cfd is employed to investigate the effects of the area ratio of the ejector constantarea mixing section to the nozzle throat, the length of the. The leaves translate on a rollertrackcage arrangement, causing a change in the nozzle convergence angle fig. Gea jet systems are reliable and require low maintenance. A that the entry speed can be neglected, only modifies the flow inside the nozzle, but not the exit conditions. The control of the area ratio is achieved by a movable spindle installed in the primary nozzle. When they leave the turbine, the combustion gases have still some remaining pressure which is converted into speed by a convergent contour of the nozzle. Ar decides the velocity and pressure of the driving flow at the nozzle exit. A propelling nozzle is a nozzle that converts the internal energy of a working gas into.
Controlling ejector performance pumps operating on the ejector principle are in use on many processes. Pdf effect of nozzle exit position nxp on variable area mixing. The application potential of ejectors in other areas of interest remains. All stainless steel vacuum ejector smc corporation.
The ejector is a mechanically simple mixing device which may be analysed using compressible flow theory. Steam expands in a set of nozzle from 10 bar, 300 0c to 1 bar. For this test it was required that the nozzle be held at a well defined minimum area under all loads, but also it must be able to hold a progra mmed area up to 20% larger as. Experimental results with the first laboratory scale variable geometry ejector vge using isobutane r600a are presented. Pdf a number of numerical and experimental studies have been devoted to the modeling of highperformance steadyflow ejectors in different. If the amount of leakage is known based on the effective sectional area of the side with the leakage, the vacuum pressure can be estimated in accordance with the ejectors flowrate characteristics. Predicted performance of a thrustenhanced sr71 aircraft with an. This result implies that each of the cavities could pump the same. Propelling nozzles may have a fixed geometry, or they may have variable.
Tests were conducted at nozzle pressure ratios ranging from. As a specific result, they found that for a fixed geometry, the ejector is very. Jot ames research center national aeronautics and space administration washington, d. Experimental study on a multievaporator refrigeration. An efficient nozzle provides high kinetic energy at the nozzle outlet for high pressure recovery in the ejector. Analysis on performance characteristics of ejector with. In this work, three geometrical factors the area ratio between the nozzle and constant area section, nozzle exit position and constant area section length were considered. Theoretical and experimental investigations of different. Study on the performance of a variable geometry ejector. The objective was to validate the unstructured solver for the ejector nozzle flow. Why are adjustable area jet engine nozzles mostly limited to.
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