Circulating Water Tunnel – CWT

NTNU’s new Circulating Water Tunnel is the first test tank at the Marine Technology Center where the use of optical flow measurement systems (like PIV or LDV) was considered right from the planning phase. Hence, the tank comprises an entirely transparent, rectangular test section that can be observed from downstream as well. It was manufactured by Engineering Laboratory Design US  and installed in the spring of 2010.

For teaching purposes, there is a flow visualization kit installed and several student workplaces are prepared.

Figure 2

Photo above: Dye visualization of the Vortex Street behind a circular cylinder. See Figure 1 below.

Specifications:

  •  All over size (L x W x H): 9.10 x 3.00 x 2.10 m
  •  Test section size: 2.50 x 0.61 x 0.61 m
  •  Low turbulence level of 1% of free stream velocity
  •  Velocity profile outside boundary layers +/- 1% of mean velocity
  •  Flow speed from 0.03 to 1 m/s
  •  Operation with free surface or closed lid.
  •  The ambient pressure can’t be lowered – it is not a cavitation tunnel

Usage

The lab will be used for fluid flow demonstrations, as student lab in courses and in PhD research projects. Special attention is paid to projects integrating EFD and CFD.

Location

The lab is located in the basement of the Structural Laboratory building at the Marine Technology Centre at Tyholt.

Operation

The lab is operated by NTNU Department of Marine Technology, in co-operation with MARINTEK. For technical inquiries contact Jan Visscher or Professor Bjørnar Pettersen.
 

Figure 1

Circulating Water Tunnel Lay-out (Click to englarge)

Figure 1

Figure 2

PIV measurement seen from the side.

Figure 2

 Figure 3

PIV measurement seen from downstream.

Figure 3