Fluid Mechanics Laboratory and Wind Tunnel

Department of Energy and Process Engineering

Fluid Mechanics Laboratory and Wind Tunnel

Norway's Larges Wind Tunnel. Photo: Geir Mogen/NTNU
Wind turbines in Norway's largest wind tunnel of its kind. Photo: NTNU/Geir Mogen.

The NTNU Fluid Mechanics Laboratory is housed within Strømningsteknisk on the Gløshaugen campus. It includes several facilities designed for the investigation of fundamental fluid mechanics problems.

Facilities

Facilities

Large-Scale Wind Tunnel
The wind tunnel (left), flow separating from an iced airfoil (middle)and particle image velocimetry experiment (right)Photo credits in order left to right: Jason Hearst (1,3), Magnus K. Vinnes (2).

The Large-Scale Wind Tunnel at NTNU is the largest wind tunnel of its kind in Norway. It is primarily used for research. Some past studies have focused on measurements of the flow around model wind turbines, aerodynamics of airfoils, bridge aerodynamics and fundamental turbulence measurements. The wind tunnel is also used for teaching, particularly in the courses TEP4175 Wind Turbine Design and TEP4160 Aerodynamics. The wind tunnel is presently undergoing significant refurbishment but is still in active use (2020).

Contact: Jason Hearst

 

Water Channel
Water channel (left), 3D model of the water channel (top right), and instantaneous turbulent production field (bottom right). Photo credits in order left to right: Jason Hearst (1), Leon Li (2) and Madeline Zhang (3). 

Water has slower dynamics than air, making it easier to study fluids problems including turbulence. The recirculating open water channel is equipped with an active grid, which enables control of the flow and turbulence conditions in the water channel. The facility is designed to study the development and decay of turbulence and how turbulence affects immersed objects. The water channel has full optical access, making it easy to use with modern optical laser-diagnostics. The floor was designed to be smooth and level, making the facility ideal for wall-bounded flow studies. The facility also has a towing rig.

  • Test-section dimensions: 1.8 m x 0.8 m x 11.2 m (width x height x length) 
  • Maximum velocity: 1 m/s (2 knots) 
  • Special features: Active grid turbulence generator, 3 axis traverse, towing rig (1 m/s) 

Contact: Jason Hearst

 

 

Von Kármán Mixing Tank
Photo credits: Jason Hearst (left), Pawel Baj (two illustration to the right) 

The von Karman tank produces stationary, homogeneous turbulence conditions with relatively large Reλ (up to 1000) in its central region. Such conditions are relatively close to homogeneous isotropic turbulence, as considered in many DNS studies, and therefore are suitable for fundamental turbulence research. The impellers can be operated in several modes (e.g. steady rotation, modulated rotation, random rotation), which provides control over the forcing mechanism. This facility was originally located at the University of Cambridge but has been relocated along with its original researchers (Prof. Worth and Prof. Dawson) to NTNU. 

Contact: James Dawson

Non-Newtonian Towing Rig
Photo: Jason Hearst (left), Olav Rømcke (two illustrations to the right) 

The non-Newtonian towing tank has been used to measure the propagation of jamming fronts in dense cornstarch suspensions. Jamming fronts generated around a towed cylinder have been studied, but the setup is also intended for use with other towed bodies and fluids. 

  • Test Section Dimensions: 0.5 m x 0.5 m x 1.1 m (width x height x length)
  • Towing speed: 4 m/s (max)
  • Sample publications: Rømcke et al. (2020)

Contact: Jason Hearst

 

 

Wave-Current Tank
Photos and illustrationsBenjamin Keeler Smeltzer 

The wave-current tank has been used for studying water waves propagating atop vertically-sheared currents. Previous experiments have measured ship waves and ring waves in the presence of shear currents, confirming theoretical predictions. In addition, measurements of the directional wave spectrum have been used for developing and testing remote sensing methods of vertically-sheared currents. 

  • Test-section dimensions: 2 m x 2 m x 0.15 m (length x width x height)
  • Maximum velocity: 1 m/s
  • Special features: Flow-conditioning systems to produce vertically-sheared currents of different forms. Experimental techniques for measuring the topography of the water surface in space and time.
  • Sample publications: Smeltzer et al. (2019a), Smeltzer et al. (2019b)

Contact: Simen Ellingsen

Gunt Aerodynamics Tunnel
Photos: Jason Hearst 

The small GUNT aerodynamics tunnel is primarily used for teaching. It has a series of built-in infrastructure making it ideal for student demos and exercises. This is a commercial product made by GUNT GmbH and more details can be found here. It is used in the teaching activities of FENT2002FENA2002FENG2002 Fluid Mechanics & Hydraulics. 

  • Test-section dimensions: 0.29 m x 0.29 m x 0.42 m (width x height x length)
  • Maximum velocity: 28 m/s
  • Special features: Integrated force balance, pressure measurements, and smoke wand

Contact: Tania Bracchi

Small-Scale Channel Flow Facility
Photos and illustrations: NTNU (left), Olav Rømcke (top right), Masour Asadi (lower right) 

The small-scale channel flow facility was designed to investigate canonical channel flows. The facility has full optical access and includes an active grid at the inlet where each wing is independently controllable.  There is also a movable injection plate where different gases can be mixed into the flow or suction or blowing can be applied. The closed channel test-section can also be removed, thus creating a planar jet facility with an active grid.  This facility was funded by the NFR Project DiHi-Tech. 

  • Test-section dimensions: 0.6 m x 0.05 m x 6 m (width x height x length)
  • Maximum velocity: 20 m/s
  • Special features: Active grid with each wing controlled independently. Porous wall for gas or air injection. Complete optical access. Can also be configured as a planar jet.

Contact: Jason Hearst

 

 

Small-Scale Wind Tunnel
Photos: Jason Hearst (left), Magnus K. Vinnes (both photos to the right)

The aerodynamic wind tunnel at NTNU is a small tunnel intended for aerodynamic style measurements. It contains multiple force balances and has been used for various aerodynamic studies in the past, including sports garments aerodynamics, sports helmet aerodynamics, and small-scale wind turbine aerodynamics. 

  • Test-section dimensions: 1 m x 0.5m x 5 m (width x height x length)
  • Maximum velocity: 35 m/s
  • Special features: 6 component force balance
  • Sample publications: Skeide et al. (2020)

Contact: Jason Hearst

 

 

green lasers and person with protective glasses
Wind turbine in the wind tunnel (left) and experiment with laser in the water channel (middle and right). Photos from the left: Jason Hearst, Abhijat Verma, Milad Samie.

The Fluid Mechanics Laboratory at NTNU is extremely well equipped.  In addition to the active grids and force balances directly integrated into the various facilities, the lab has moveable measurement equipment including: 

Particle Image Velocimetry (PIV) systems: 

  • 20 kHz, 1 MP stereo PIV system 
  • 10 kHz, 1 MP tomo PIV system 
  • 1 kHz, 4 MP stereo PIV system 
  • 15 Hz, 16 MP stereo PIV system 
  • 15 Hz, 4 MP (16-bit) stereo PIV system 

Laser-Induce Fluorescence (LIF) systems: 

  • The above systems can also be used for LIF, which we primarily do in water using Rhodamine 6G. 

Hot-wire anemometry (HWA) systems: 

  • Dantec StreamLine Pro constant temperature anemometry (CTA) systems – 8 channels 
  • Numerous single-wire and X-wire probes for use in air. 
  • Numerous single-wire and X-wire probes for use in water. 

Laser-Doppler Anemometry (LDA) systems: 

  • 2-component LDA system. 

Designing wind turbines

Designing wind turbines

A film from the course Energy from Environmental Flows.

Student interview: wind tunnels

Student interview: wind tunnels

Student interview: water channel

Student interview: water channel