The EFM group has long relied on state-of-the-art computational facilities and experimental equipment. However, it's worth remembering that "state-of-the-art" means different things at different times, so below we have showcased just some of the equipment that has shaped the group into what it is today.
This
shows an early programmable Soviet calculator, purchased on the black market
by a specially commissioned undercover agent, which was used in many of the
original two-free surface computational problems. This is one of the reasons
why the frontal solver was first selected as a computational technique,
allowing a massive three elements to be used to discretise the fluid domain.
However computational time was excessive, requiring over 9 hours of processing
time and consequently a battery the size of a large suitcase
was needed in addition to the small hand-held unit.
Things move rapidly in the
computing world though, and before long the funds became available to buy a
modern day computer which is still in use in room X311. This featured a "disc
drive" (actually a modified record player) and a computer screen that was
capable of showing streamline plots by plotting out the multiplication sign at
various points on the screen.
A streamline plot showing a saddle point within a flow.
Lets leave the computational side of things now, and have a look at some of
the early experimental equipment. One of the first things we looked at was
forward roll coating. Once again, a practical solution to procuring the
necessary equipment was found. One of the group members posed as a mangle
repair man at the local swimming baths and was unable to repair the cracked roll on
site. This meant it had to be "removed to the workshop" for the "repairs" to be
carried out. Unbeknown to the swimming pool attendants it was located in the basement of
the Mechanical Engineering department, and an intensive 2 weeks followed where
flow structures between contra-rotating rolls were studied in considerable depth.
One PhD student rotated the handle at a constant speed whilst a second
injected blue ink into the flow using nothing more than a drinking straw. This
technique was later adopted by a number of prominent workers. At the end of
this the mangle was returned to the baths with a "new" blue roll, without them
even realising what had gone on !!
The first "motorised rig" the group owned was an early spin-coating machine.
Again this was a modification of a highly sophisticated machine that was on
the market at the time - a "washing machine". The picture highlights the elegant
lines that this machine was designed on. Initially there were some vibration
problems, but once we discovered that a member of the academic staff (who
shall remain nameless) had been using the machine
for his laundry and removed his AC/DC T-shirt from around the central spindle
the rig gave years of service. The rest, as they say, is history!