Experimental Study of Aerodynamic Behavior Downstream of Three Flow Conditioners

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.

2015 ◽  
Vol 81 (826) ◽  
pp. 15-00091-15-00091 ◽  
Author(s):  
Yuki WADA ◽  
Noriyuki FURUICHII ◽  
Yoshiya TERAO ◽  
Yoshiyuki TSUJI

Author(s):  
Boualem Laribi ◽  
Nahla Bouricha

This work describes the effect of a Tee and a Valve on the flow measurement accuracy and the performances of the E´toile flow straightener described by the standard ISO 5167 to produce the fully developed pipe flow with these disturbances. Simulation is carried out for an air flow in 100mm pipe diameter with a Reynolds number between 104 and 106. The code used for this work is Fluent V6.3, where the Navier-Stokes equations are solved by the finite volumes method with K-ε model like turbulent model. The results show that for the disturbance valve 50% closed, the length of establishment seems to be reached at 25D downstream the E´toile where the flow gyration angle is reduced practically to zero value. But for the Tee disturbance the results show that the flow needs more than 25D to reach the profiles requested by the standards. An experimental study is essential to validate these results for choosing a standard disturbance which will be examined with conditioners quoted in standard 5167 and thereafter the development of a new flow conditioner.


1965 ◽  
Vol 180 (1) ◽  
pp. 331-356 ◽  
Author(s):  
L. J. Kastner ◽  
J. C. McVeigh

In view of the importance of accurate measurement of flow rate at low Reynolds numbers, there have been numerous attempts to develop metering devices having constant discharge coefficients in the range of pipe Reynolds numbers between about 3000 and 200 and even below this latter value, and some of these attempts have achieved a reasonable degrees of success. Nevertheless, some confusion exists regarding the dimensions and range of utility of certain designs which have been recommended and further information is necessary in order that the situation may be clarified. The aims of the present investigation, which is believed to be wider in scope than any published in this field in recent years, were to review and correlate existing knowledge and to make an experimental study of the properties of various types of orifice in the low range of Reynolds numbers. Arising from this it was hoped that a design might be evolved which not only had a satisfactorily constant discharge coefficient throughout the range but was also simple to manufacture and reproduce, even for small orifice diameters of the order of 0.5 in or less, and it is believed that some success in attaining this aim was achieved. The first section of the paper contains a review of previous investigations classified into three main groups. In the second part of the paper, experiments with various types of orifice plate are described and it is shown that a properly proportioned single-bevelled orifice has as good a performance in the low Reynolds number range as that of any of the more complicated shapes.


2003 ◽  
Vol 125 (1) ◽  
pp. 189-191 ◽  
Author(s):  
Gerald L. Morrison

A new relationship for orifice flow meter discharge coefficients has been developed which replaces the Reynolds number dependence with the Euler number. Both relationships have the same accuracy for the calculation of the discharge coefficient but the new relationship eliminates the need to know fluid viscosity.


2021 ◽  
Author(s):  
Alessandro Ceci ◽  
Sergio Pirozzoli ◽  
Joshua Romero ◽  
Massimiliano Fatica ◽  
Roberto Verzicco ◽  
...  

2000 ◽  
Vol 123 (2) ◽  
pp. 238-248 ◽  
Author(s):  
Oguz Uzol ◽  
Cengiz Camci ◽  
Boris Glezer

The internal fluid mechanics losses generated between the blade plenum chamber and a reference point located just downstream of the trailing edge are investigated for a turbine blade trailing edge cooling system. The discharge coefficient Cd is presented as a function of the free-stream Reynolds number, cut-back length, spanwise rib spacing, and chordwise rib length. The results are presented in a wide range of coolant to free-stream mass flow rate ratios. The losses from the cooling system show strong free-stream Reynolds number dependency, especially at low ejection rates, when they are correlated against the coolant to free-stream pressure ratio. However, when Cd is correlated against a coolant to free-stream mass flow rate ratio, the Reynolds number dependency is eliminated. The current data clearly show that internal viscous losses due to varying rib lengths do not differ significantly. The interaction of the external wall jet in the cutback region with the free-stream fluid is also a strong contributor to the losses. Since the discharge coefficients do not have Reynolds number dependency at high ejection rates, Cd experiments can be performed at a low free-stream Reynolds number. Running a discharge coefficient experiment at low Reynolds number (or even in still air) will sufficiently define the high blowing rate portion of the curve. This approach is extremely time efficient and economical in finding the worst possible Cd value for a given trailing edge coolant system.


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