We are getting ready to test some of the components
of a turbo compound engine. What we plan to do
is install a gear box on a turbo charger mounted
on an engine and connect the output of the gear box
to a generator to act as a turbo charger dyno if
you will. We want to make sure the gear box works.
We will also instrument the turbo charger
for TIT and RPM.

The air output of the compressor will
be connected to a valve to simulate the intake
system. In other words the engine will not
be turbo charged. We are merely using a normally
aspirated engine to drive the turbo charger.

This is done to prevent a turbo charger
turbine or bearing failure from generating scrap
aluminum that will find its way into the engine.
We don't want to be overhauling the engine
every time a turbo charger fails.

My problem is: what do I use for a generator
that will handle 50 HP or 37 KW.
Also what do I use for a load.
I could use 37 one KW electric room heaters.

Anybody have any ideas?

Paul Lamar


Paul,

If you get a generator sorted, you could use a 55 gallon drum of water as
a dummy load,
the drum is one terminal, you then lower a steel plate to, the other
terminal, to get the desired
resistance for the correct load. We use them as dummy loads in high power
electrical testing.

At 110 V, you may need to add a bit of salt to get the conductivity
required. If my math is right,
at 37kw, a 10 degree centigrade rise in water temp would take 3.8 minutes.


Brian. in Oz

Wow Brian. I never heard of that. A real cheap electrical load.
What voltage are you using? Does it work with AC? DC?
We could measure the torque on the generator housing directly.

Paul Lamar


It is cheap & nasty. Works with AC or DC, we use it to control
large circuit currents up to several hundred volts during testing.
Like a bucket on a well, there was a roller system to lower a& raise the
plates to get the desired load. We use three symmetrical plates,
for three phase systems. In the old days was also used to
limit fault currents in power systems.

Years ago you used to be able to buy electric kettles that consisted of
two parallel SS plates, the natural impurities in the water were
conductive enough to heat the water with no problems of burn
out if the water ran dry.

As the water is purely resistive, simply measure the voltage and current,
multiply them and you get real power flow, assume generator efficiency of
80%? and there is your input power.


Brian in Oz.

Thanks Brian a very intriguing idea.

Paul Lamar