Session: FSI-02-03 Vortex Shedding

Paper Number: 123311

123311 - Flow Induced Pulsation in Jet – Header Configuration 

Flow Induced Pulsations can be generated due to the interaction between the acoustic field and a shear layer.  This occurs for instance at Tjoints. Very high amplitudes can be generated at Tees depending on the configuration of the Tee.  Important factors include the flow field orientation to the acoustic field. Configurations with a high amplification factor are for instance the cross (sidebranches across from each other) or the  double tee separated by a half wavelength in which the sidebranches form a ¼ lambda resonance mode. One configuration encountered in the field often is a header with a number of inlets. In the field it has been difficult to predict the occurrence of the high amplitude pulsations in different geometries. For this configuration (t-6, D. Tonon) experimental data has been generated by D. Tonon only for equal diameter of the sidebranch and header. Therefore a large number of questions remain:

-          What is the influence of the inlet diameter? What is the correct length scale for the interaction. Is this the sidebranch or the header diameter. Or is the interaction more jet-like like rather than plane shear layer like?

-          What is the influence of the inlet position? How sensitive is the amplification factor for the position of the inlet to the acoustic velocity field?

-          What is the influence of the outlet position? Ideally the header modes are limited to the header but of the diameter of the outlet is large enough, also the outlet plays an important role in the acoustic modes. Therefore the location of the outlet compared to the acoustic field is important.

To that a flexible configuration was build (3000mm long 150mm header) which allowed the variation of inlet diameter (25, 50, 75mm) , inlet position (100, 250, 500, 1000mm) and outlet position (1500, 2250, 2910 mm). Flow experiments were done for almost all combinations with for the small inlet ID velocities up to 130 m/s and the largest inlet ID up to 30 m/s.  

The configuration did show a coupling between the acoustic field and the inlet flow although the amplification was low at maximum p = 0.1 ½ ru²_. The amplification factor was maximum for the large inlet diameters with the outlet in the middle of the header. The outlet location did have a large influence on which modes were excited mostly.

Presenting Author: Stefan Belfroid TNO

Presenting Author Biography: Stefan Belfroid is an experienced engineer with 25 years experience in the oil & gas industry. He is active in different fields ranging from multiphase flow and flow-induced pulsations. He has been presenting at the ASME-PVP since 2006.

Authors:

Stefan Belfroid TNO
Ronald Driessen TNO
Nestor Gonzalez-Diez TNO
Bart Van De Krol TNO