THEORETICAL AND EXPERIMENTAL STUDY OF A RESONATOR MODEL FOR ATTENUATION OF PRESSURE WAVES IN THE PRESENCE OF PULSATING FLOW ORIFICE PLATE

Author(s):  
Mara Nilza Estanislau Reis ◽  
Amanda Maria Araújo Mendes ◽  
Brenno de Rocha Brito ◽  
Yuri Veríssimo Soares
Author(s):  
Omkar S. Gokhale ◽  
Milind A. Jog ◽  
Raj M. Manglik

Experimental study of air bubble formation from orifice plates submerged in water pools has been carried out. Air is forced through the orifice by supplying it to a chamber connected to the orifice plate. The chamber volume plays an important role in determining the bubble growth time as well as bubble size and shape at departure. The effect of chamber volume is generally correlated in term of a dimensionless parameter, capacitance number (Nc), which is proportional to the chamber volume and is inversely proportional to the square of the orifice diameter. To better understand and characterize this effect, an experimental study is performed using ten orifice plates of diameter ranging from 0.61 mm to 2.261 mm with six different chamber volumes between 12 cc and 59 cc with the corresponding capacitance numbers varying from 0.2 to 19. The shape and size of the bubble are captured using high speed videography. The orifice plate material is acrylic glass which has an equilibrium contact angle of 38° with pure water. It was observed that the value of critical capacitance number or Nc above which the bubble evolution is affected by the gas chamber volume, is around 0.85. The bubbles are more spherical in shape, and the growth time is significantly smaller. Also, at high capacitance number (Nc > 7), the air flow in the bubble is so high that the bubble departs with a sharp apex and has a large volume. Above Nc > 10, the chamber effects plateau and further increase in gas chamber volume does not alter bubble size and shape at departure.


Author(s):  
Boualem Laribi ◽  
Pierre Wauters ◽  
Mohamed Aichouni

The present work is concerned a comparative study of the decay of swirling turbulent pipe flow downstream of three flow conditioners, the Etoile, the Tube bundle, and the Laws perforate plate, and its effect on accuracy of orifice plate flow meter. The swirl was generated by a double 90° degrees elbows in perpendicular planes. The discharge coefficients were measured with 3 different orifice meters with β = 0.5, 0.62, 0.70 at different Reynolds number. As a conclusion, the experimental study of the three flow conditioners used separately shows that the flow need longer distance for close to fully developed pipe flow and some errors, by reason of the swirl, on the discharge coefficient were inevitable for distance less 12D.


2013 ◽  
Vol 454 ◽  
pp. 230-233
Author(s):  
Jian Jun Liang ◽  
Shu Liu ◽  
Xin Sheng Jiang ◽  
Dong Wang ◽  
Jian Zhong Zhou

In this paper, the process of the gas explosion waves was investigated in a closed pipeline. The research indicated that the interaction between pressure waves and flame waves were extensive in the course of gas explosion, which took effect of both enhancement and inhibition, and played a leading role at different stages. Not only could the flame waves raise the pressure peak and amplitude, but they also compressed the ascent stage of the pressure waves, stretched the descent stage. Eventually, detonation waves may come into being.


2014 ◽  
Vol 699 ◽  
pp. 915-920 ◽  
Author(s):  
Bukhari Manshoor ◽  
Mohd Fahmi Othman ◽  
Izzuddin Zaman ◽  
Zamani Ngali ◽  
Amir Khalid

The plant industry is required to measure flow rate more accurately to meet plant operation and cost accounting objectives. The opposing concern of improving flow meter accuracy is resolved by using flow conditioners. The distance of implementation of flow conditioner upstream of the orifice plate flowmeter is also need to be addressed. Hence, in present study, an analysis of the porosity of fractal flow conditioner towards orifice plate flowmeter’s accuracy and the best distance of fractal flow conditioner upstream of the orifice plate flowmeter was determined. In an experimental work, a different porosity of the fractal flow conditioners were installed with different distance upstream of the orifice plate in conjunction with the different disturbances to assess the effects of these devices on the measurement of the mass flow rate. Data gained for all the plates showed that there is increment of pressure drop and change in discharge coefficient of the orifice with lower β value of fractal flow conditioner. Good comparisons with the previous experimental work demonstrate the fractal flow conditioner can preserve the accuracy of metering up to the level required in the standards.


Author(s):  
Fuyang Tao ◽  
Xin Zhang ◽  
Phillip Joseph ◽  
Oksana Stalnov ◽  
Matthias Siercke ◽  
...  

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