Göttingen U-Boot
The Göttingen U-Boot is a general-purpose pressure vessel. It can be filled with helium, nitrogen or sulfur hexafluoride (SF6) up to the maximum rated pressure of 19 bars with a stability of ± 0.01 bar over several days. The internal temperature of the vessel is actively controlled to within ± 0.05 ˚C as measured at a single location. Electrical/optical cables and water/gas pipes can be fed through the wall of the pressure vessel. No optical viewports are available.
It has been designed to house different experiments. As in the turbulence tunnel, all equipment, from heat transport and particle image velocimetry to 3D-Langrangian particle tracking, can be used inside the vessel. Experimental inserts available include two turbulent cylindrical Rayleigh-Bénard experiments (diameter 1.1m, height 2.2m and 1.1m respectively) that reach Rayleigh numbers as large as Ra ∼ 1015.
 |
Figure 1: a photo of the pressure vessel in blue wrapped in black foam to provide additional thermal isolation. The vessel itself is fully pressure and temperature controlled. The 'turret' on top and the porthole on the left provide means to insert equipment into the vessel. Electrical/optical cables and gas/water pipes can be fed through the wall of the vessel. |
 |
Figure 2: dimensions of the pressure vessel in two different configurations. The configuration on the right has an extended turret, resulting in a maximum interior height of 5.1 m as measured from the flat support floor. The main cylinder has an inner diameter of 2.46 m and the turret has an inner diameter of 1.46 m. |
Specifications:
Total length: 5.3 mStraight cylinder length: 4 m
Straight cylinder inner diameter: 2.46 m
Max. height turret: 5.1 m
Turret inner diameter: 1.46 m
Pressure range: 1 mbar - 19 bar,
Temperature range: 20 – 35 °C
Cooling power: up to 50 kW
Kinematic viscosity of SF6 at 15 bar: 1.5×10-7 m2/s.
External users are welcome. Please contact Dr. Stephan Weiss for details.