Experimental and Numerical Analysis of Hydraulic Transients in the Presence of Air Valve

Wéber, Richárd; Hős, Csaba

doi:10.3311/ppme.10336

Cited by 6 publications

(2 citation statements)

References 2 publications

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“…Despite the widely available application range of safety valves [2][3][4], their sizing in the case of multi-phase is still ambiguous matter and hard to predict because of the complexity of multi-phase flows nature, as stated, e.g., in [5]. The unpredictable fluid mixture flashing (evaporation) due to the sudden pressure drop through the valve causes a phase change which in turn may result in valve chattering, leading to insufficient venting capacity and eventually to the catastrophic rupture of the system (undersizing and oversizing of safety valves), see, e.g.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow

Burhani

Hős

2021

Period. Polytech. Mech. Eng.

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Due to the low number of experimental investigations on the sizing of safety valves in multiphase flow, a novel set of measurement data of an air-water mixture is reported. This paper presents an experimental study on three different geometries of safety valves, a poppet valve with jet angle θ = 120°, and two-disc valves with deflection angles θ = 0° and θ = 90°, respectively. Our test rig comprises a pipeline with 42.5 mm inner diameter, spray nozzles to supply the added water quality (water mass fraction) to the pressurized airflow up to 40 % mass fraction and an inlet pressure up to 6.6 bar(g). The time histories of force, valve lift, and pressures were recorded. We present correlation data for the force coefficient and the discharge coefficient. The widely used omega technique for the Homogenous Equilibrium Model (HEM) is employed to predict the theoretical mass flux. The results show that the poppet valve experiences less momentum force and lower mass flow rates compared to disc valves, while the disc valve with deflection angle θ = 90° presents the highest discharged flow rates among the tested geometries. Our most important finding is that up to 60 % relative valve lift and 40 % mass fraction, neither the force nor the discharge coefficient changes significantly compared to the pure-air case. Finally, we propose a new correlation with a single equation for the resultant force and the discharge coefficient as a function of the relative valve lift for all tested water mass fractions.

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Section: Introductionmentioning

confidence: 99%

An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow

Burhani

Hős

2021

Period. Polytech. Mech. Eng.

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“…Wéber and Hős [25] investigated experimental and numerical analysis of hydraulic transients in the presence of air valve.…”

Section: Introductionmentioning

confidence: 99%

Design of Discrete Wavelet by Using Transient Model for Exact Measurement of Manufacturing Faults of Tapered Roller Bearings

Deák

2019

Period. Polytech. Mech. Eng.

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This paper considers a comparison of six wavelets for bearing fault diagnosis. Five wavelets Symlet_05, Symlet_08, Daubechies_04, Daubechies_06, Daubechies_08 are typical ones which are used for fault diagnosis due to several researches. The purpose is to design a new discrete wavelet which has higher efficiency to reveal minor defects on the bearing rings. Defects derive from either manufacturing or operational problems. Detecting of tiny manufacturing defects, especially manufacturing grinding marks is quite difficult due to their special geometrical shapes, however they can cause serious problems in machines during operation. Therefore, it is an important task to diagnose these marks with the most adequate methods. The transient vibration signal model of the defect is established for signals generated by tapered roller bearing on the outer race. The wavelet creation used the sub-optimal algorithm devised by Chapa and Rao. The applicability of the matched wavelet is tested for identifying this kind of bearing failure. The new wavelet analysis and synthesis filter coefficients are determined which define the designed wavelet. To determine the efficiency of the designed wavelet and to establish comparison with the other wavelets, a test-rig was constructed with high-precision measuring sensors and devices. By using the Maximum Energy-to-Shannon Entropy criteria the efficiency of the wavelets is determined. The designed wavelet is found to be the most effective to detect the manufacturing fault compared to the others in this article. The final purpose is not only to detect the faults but to determine their sizes. By analyzing the entry points of the rollers into the defects, the de-stressing point and the exit points of the rollers from the defects the width of the grinding marks is calculated. It is proved that the new-designed wavelet obtains the most precise way for fault width measurement. Finally, the size of the failure is measured by a contact type Mahr Perthometer to compare the results to the calculated parameters and validate them. The width deviation is only 1.18 % in the case of the new-designed wavelet which is remarkable precision level for bearing fault analysis.

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Modification in gate valve using flexible membrane pipe for flow measurement

Bhilare¹,

Hinge

Kumbhalkar³

et al. 2021

SN Appl. Sci.

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A gate valve is used to regulate discharge in pipelines. It is rotated by a wheel that is attached to a circular disc (i.e. gate) at the top of a stem. Each revolution of the wheel creates a particular linear disc movement that changes the flow zone. The paper describes the journey of gate valve from flow control device to flow measuring device and presents an experimentation on conventional gate valve and gate valve with flexible membrane pipe. The findings of experimental study are described and validated with CFD analysis of conventional and modified gate valve. The experimental study has shown that the modified gate valve can be used as flow measuring device. The results obtained represent the excellent improvement in the relationship between disc position (i.e., angle) and discharge. The results of CFD analysis for flow through gate valve with and without flexible membrane are compared. After carrying out the CFD studies without flexible membrane, it is found that, fluctuating separation zones formed on either side of gate are responsible to a great extent to the flow rate descripancies. This paper compares the experimental and CFD results and also suggests the remedy to address the problem. Article highlights Introduced simply a flexible membrane pipe inside PVC to convert gate valve into flow measuring device. Reduction in flow separation and fluctuation in flow rate. Smooth flow rate even though gate valve opening is small.

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Experimental and Numerical Analysis of Hydraulic Transients in the Presence of Air Valve

Abstract: Abstract

Cited by 6 publications

References 2 publications

An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow

An Experimental Study on the Force Coefficient and the Discharge Coefficient of a Safety Valve in Air-water Mixture Flow

Design of Discrete Wavelet by Using Transient Model for Exact Measurement of Manufacturing Faults of Tapered Roller Bearings

Modification in gate valve using flexible membrane pipe for flow measurement

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