Post by jetric on Oct 24, 2019 9:37:41 GMT -5
turbinecar.com/wiggins.htm
Edit: I've found what I think is a solution from a Wikipedia article
"The free-turbine engine was particularly favoured. It did not require a clutch, as the gas generator could be spun up to operating speed without requiring the output shaft to rotate. For the Wessex this was used to give a particularly fast take-off from a cold start. By locking the main rotor (and the power turbine) with the rotor brake, the engine could be spun up to operating speed, then lit, and when the engine core is at the operating speed of 10,500 rpm the brake is released and drive to the rotor smoothly increased as the power turbine gains speed. This was used to bring the rotor to speed from stationary in just 15 seconds and a time from engine start to take-off of only 30 seconds.[2]"
With the Rolls Royce Gem engine I think this would be a valid option for race and drag.
But being a simple direct drive we have the fuel problem again with having the turbine at idle with low speeds..
Could the main rotor be restricted to restrict speed?
This dilemma of fuel efficiency led me to cvts...
-John
Think of the freepower turboshaft turbine engine as a piston engine with a torque converter, the piston engine can still run at idle with the torque converter output stationary, the output from the piston engine torque converter is the same as the output from the freepower turboshaft turbine engine, the main turbine engine can run at idle with the freepower output shaft stationary.
Did you not see the video that I put up on a previous post to you of the slingshot dragster fitted with a Rolls-Royce Gem turboshaft engine. I gave the owner advice on the installation of this engine, the output from the engines freepower turbine is directly coupled to the input shaft on the Differential via a gearbox that is only there to provide a reverse gear to allow him to return the dragster back to the start line after a burn-out, other than that it is directly coupled. Watch the video and see how fast it leaves the line, he holds the dragster on the brakes at the line and raises the turbine engine rev's to nearly full power with the freepower turbine stationary then releases the brakes!!!!---- Gone!!
The Gem engine is capable of producing around 1000ft/lbs of torque with the main turbine engine at full power with the freepower turbine stationary(stalled) and a maiximum of 1000 to 1200HP at 6000rpm output shaft speed depending on the model. Your transmission will have to be capable of coping with this power and torque.
As for fuel consumption all turbine engines use vast quantities of fuel, this is a trade off for the excellent power to weight/size and reliability of the turbine engine compared to the piston engine. If you want an economical vehicle use a diesel piston engine instead!!
Did you contact my friend who has the RR Gem engines for sale?
Hope this helps,
Richard S.
