Department of Energy and Process Engineering

Multiphase Flow Laboratory

The Multiphase Flow facilities are located in the Thermal Engineering Laboratory at NTNU. The laboratory has been developed by Professor Ole Jørgen Nydal (Industrial Process Technology Group). See also Subsea Working Group.

Oil-water-air flow in pipes

Oil and water are circulated with centrifugal or displacement pumps and metered before mixing with air at the inlet of the test sections. The air is taken from the central supply at the university and the pressure is reduced from about 7 bar to about 3-4 bar in a buffer tank.

The air and the liquid streams can be routed to straight pipes (3,6,9 cm ID) mounted on an aluminum beam, or to a pipe configuration for severe slugging mounted on the wall (5 cm ID). Two S-shaped geometries are available, one in acrylic pipes and on e in steel, for slug control tests where a topside valve can lead to pressurization (4 bar) of the system.

Impedance probes are used for holdup measurements, flush ring probes and external capacitance based clamp-on probes.

The main purpose of the loop is to provide a flow laboratory for students and researchers (projects, MSc, PhD, PostDoc.) and a demonstration facility which can be used for education purposes.

The loop is operated through a Labview interface.



The main specifications of the laboratory are given in the table below.

Test sections

Straight Acrylic

3, 6, 9 cm  ID, 16 m long, +- 15° inclination


Acrylic, Steel, 5 cm ID, 16 m long, 7 m high


Air from central system , tap water, oil

Flow rates


0.5 – 30 m/s  (vortex meter and coriolis meter)


0.02 – 2 m/s (2 electromagnetic meters)


0.02 – 2 m/s (2 coriolis meters)




Liquid circulation

4 centrifugal pumps, 2 positive displacement pumps, frequency controls, 2 dosage pumps
Overflow arrangement for pressure controlled liquid flow


Central supply, 7 bar


3 m3 tank for gravitational oil/water separation
Air ventilation system

Buffer tank

Air buffer tank on low pressure side, for variation of the frequencies of terrain slugging

Data acquisition and control


Lab-view based data aquisition. Fast DAQ cards in PC's


Field point modules. Control valves, pump frequency regulation



NetLab - Remote operating

The Multiphase Flow Laboratory can be operated remotely over the Internet.

A person in the laboratory can, after following an initiation and a safety procedure, hand over the control to a remote user.

After being granted operational control, the user can:

  • Adjust the pump frequency and valve settings for the flow of water and oil
  • Adjust the air flow valve
  • Control a moving camera along the pipe
  • Control a general web camera on the wall
  • Log time traces for predefined isntrumentation (typically impedance probes and pressure sensors) and receive them by e-mail.

Mini loop

We have made several versions of a portable laboratory the "mini-loop". A box containing a pump, compressor, separator, pressure and flow gauges. The air and water can then be connected to acrylic pipes, which is supported on allumina beams.

The main use of the loop is for educational purposes. Typical two phase flow situations can be demonstrated and students can perform exercises using the loop. Typical cases are:

  • Flow regimes (limited due to small diameter)s
  • Terrain slugging
  • Gas lift
  • Gravity dominated flows in undulating pipelines
  • Expansion driven riser instabilities

The mini-loops have also been made in student projects, where the pipes have been instrumented with pressure and light diodes. The mini  loop was also useful for severe slugging experiments in a submerged flexible riser (pool at Marin Technology).

Photo: Mini loop portable rig
Photo: Overview of the lab facilities with the miniloop in front Photo: Mini loop pipe

Model tank for flexible pipes

Demonstrated in the video below:

Model tank for flexible pipes from IVTFakultetet on Vimeo.

Visiting address

Varmeteknisk lab (Thermal Engineering lab)
Kolbjørn Hejes v. 1D, NO-7491 Trondheim