The department has a laboratory with several permanent experimental
facilities. A major facility is the MTL wind-tunnel, which is a
low-turbulence wind-tunnel with outstanding flow quality. It has a 7 m long
(1.2 m 0.8 m) test section and a maximum speed of 69 m/s. The
turbulence level is as low as 0.02 %. It is used for a variety of long-term
research projects on turbulence and laminar-turbulent transition. Among
other major facilities we may mention:
-- Supersonic wind-tunnel, 0.1m0.1m test section, 'continuously' variable Mach no. (0.7--4.0).
-- Shock tube for student laboratory exercises
-- Subsonic wind-tunnel, 0.4 m 0.5 m test section, max. speed 50 m/s.
The department shares a compressor system for the high-speed
wind-tunnels with the department of vehicle technology. There are also a
number of smaller experimental apparatuses for research and student
-- small low-speed wind-tunnel for studies of homogeneous turbulence etc.
-- plane Couette flow apparatus
-- curved rotating channel flow app. for studies of instabilities due to centrifugal and rot. effects
-- Plane Poiseuille flow apparatus (2m 1 m) for transition studies
-- a small water table for student demonstrations
-- Hele-Shaw cell and Taylor-Couette apparatus
-- a pipe-flow facility for student exercises
The measurement systems include:
-- Two Laser-Doppler Velocimeter systems
-- Hot-wire anemometers
-- Schlieren system with possibility for short duration double flash exposure.
One of the LDV systems was acquired during 92/93 and is a two-component fibre-optic system from Aerometrics. Hot-wire anemometry is used extensively and many different types of probes are designed and made 'in-house'. The smallest wires used have a diameter of 0.6m and a typical length of 0.1 mm. Data sampling is carried out mainly with Macintosh based systems.
The department has two computer systems connected to the external computer network, and consisting of about 25 workstations (SUN, IBM), (>)40 Macintosh computers and a number of X-terminals. The total capacity of the larger servers is more than 300 MFLOPS (Linpack ) with 20-25 GB disk storage available.
A significant amount of computer time has also been granted to some of the research groups within the department from international supercomputer centers.
Grants from the Göran Gustafssons Foundation has made it possible to modernize the department computers. Three computers from the IBM RS6000 series were acquired during 93/94. The largest, a model 590, has 256MB of primary memory and a performance of about 125 MFLOPs on Linpack . The smaller model 375 computer has 128 MB of primary memory. The third is a model 370 workstation. The grant from the Göran Gustafssons Foundation enabled a further step in the expansion and modernization of the department computer resources during 94/95. A model 390 workstation with 196 MB of primary memory was installed in August 1994.
The computers are available on the KTH computer network under the names obelix, idefix and asterix, respectively. Stellan Berlin (stellanb'100mech.kth.se) is responsible for the maintenance of the computers.
The department has signed a license agreement for Microsoft software as a part of a central agreement between KTH and Microsoft. It implies that we will have a continuous supply of upgrades, new versions etc of, e.g. Word and Excel. Also manuals will be supplied through this agreement (contact person: Lars Thor). The department also has licenses for a number of other softwares for a number of users that varies with the different programs. During 94/95 the department has installed the CFD programme FLOW3D from Computational Fluid Dynamics Services, AEA Technology, England with a license for ten users (on the -- ix computers).