Look I built a jet engine
- Thread starter duratothemax
- Start date
Just a little update, ive been revisiting this in my spare minutes.
My jet engine is getting a complete overhaul...
"jet engine version 2"
-New/bigger/redesigned combustion chamber
-New redesigned flame tube
-New redesigned fuel injector
-Airflow swirl inducer/evaporator mounted in the combustion chamber behind the fuel injector for better air/fuel mixing and to improve atomization. This also improves combustion efficiency and insures a more complete burn
-redesigned control panel/electronics
-redesigned oil cooler/fan
-new electric start system
-dual spark plug ignition system (my previous design only had 1 spark plug), basically it just uses the spark plugs for starting, think of them like glow plugs on a diesel engine
-BIGGER Garrett turbo off of a 12v71 detroit or something...I got it on ebay for cheap...this one has non-leaky seals and perfect bearings too. The old turbo had leaky seals and the bearings were shot which is why I retired "Ben Jet engine version 1"
With all of those improvements I decided I had to really step it up a notch in terms of engine control...
So I designed/programmed/built my own ECM.
This ECM is not some mess of resistors, timers, relays, and other ghetto'd stuff like the early analog car ECM's from the 70's-80's. It is a true fully-electronic digital ECM.
Its processor runs at blazing 8mhz, it has 128 bytes of RAM, and 4096 bytes of EEPROM. I wrote the entire operating system software from scratch. The current ECM OS is only about 1100 bytes so I have plenty of room left if I decide to add on more features or change stuff. My jet engine ECM is fully flashable, just like we can flash our dmax ECM's with EFILive.
Theres an "OBD" port on the board that I hook up to a USB port on my laptop and it takes about 5 seconds to reflash it.
Otherwise it is similar to a FADEC fly-by-wire system used on modern jet engines.
I can run it in "auto" mode, but I also have manual back up switches for the pilot injection, main injection, ignition, oil pump, and starter if I want to control everything completely manually. In addition to those manual-override switches, it also has:
-master power on/off
-auto-start button
-emergency shutdown button
-RUN/OFF toggle switch
The indicator lights on the new panel are:
-oil pump ON
-pilot injection ON
-main fuel injection ON
-ignition ON
-starter ON
-emergency shutdown light with a loud horn/buzzer
-MIL (yes, it has a check engine light!)
Gauges are:
-Turbine inlet temp (yes, its actually referred to as TIT)
-turbine outlet temp (TOT)
-combustor pressure (basically like 'boost')
-fuel pressure
-oil pressure
There are 3 "codes" it can throw:
-1 blink of the MIL/check engine light is low oil pressure (below 10psi anytime the engine is starting or running)
-2 blinks of the MIL is low combustor pressure (if its about to stall/flame out/whatever) (below 2psi when running)
-3 blinks of the MIL is high TIT (like the EGT gauge in our trucks, it sets a code if the temp gets above 1300*)
The AUTO START feature is probably my favorite. Generally, starting jet engines is a very tricky/critical procedure that almost requires 3 hands and a second set of eyes to watch all of the gauges.
All that will be required to start my engine is to first turn the 'master power' switch ON. When you turn the switch on, the ECM powers up and turns on all of the indicator lights/alarm for 3 seconds (just like your truck does when you start it). After the 'bulb test' is complete it goes into standby mode. Now you can start the engine manually with the manual-switches, or do the "AUTO-START". To auto-start the engine, just flip the OFF/RUN toggle to "RUN", and press and hold the start button for 5 seconds.
Once its in 'auto start' mode, it turns on the oil pressure and waits until it builds 35psi. Once the oil pressure is above 35psi it then turns on the starter motor (leaf blower that forces air into the cold side of the turbo) to spool up the engine. After 5 seconds of spool-up it turns on the ignition (spark plugs), and then the pilot injection (propane, its easier to light with a cold engine). After it turns on the propane it waits for the fuel to start burning. If proper light-off is not achieved within 5 seconds of turning the pilot injection on it cancels the start process and shuts down for safety. Once it sees the EGT/TIT go above 400* it determines that the engine has lit properly and waits for the combustion pressure (boost) to get above 3psi or so. Once the ECM sees the engine building boost it turns on the main fuel injection (diesel!!!). After it sees the EGT further rise above 600* or so and boost pressure get above 4 or 5 PSI, it turns off the spark plugs (because the engine is now self sustaining) and transitions to normal idle/running mode.
If at any time during the auto-start process the EGT goes above 1300*, oil pressure drops below 10psi, or the combustor PSI/boost goes below 2psi, it will turn on the check-engine light but it will still continue the start process.
IF during the auto-start sequence the boost pressure suddenly drops to zero psi, the oil pressure drops to zero psi, or the EGT continues to rise above 1400* and the engine starts to run away (called a hot start, jet engines can run away just like diesel engines), it immediately sounds the "emergency" alarm and automatically shuts down the engine.
Now that the engine is running properly you can use the throttle and speed the engine up/down/whatever.
When the engine is in normal running mode the ECM is monitoring EGT, boost, and oil pressure. If the oil pressure gets below 10psi, boost gets below 2psi, or the EGT goes above 1300*, it turns on the check engine light. If the 'driver' ignores the warning and the EGT gets above 1400*, oil pressure goes to zero, or the boost goes to zero, the ECM sounds the alarm and automatically emergency-shuts down the engine. You can also do an emergency shutdown by pressing the 'emergency shutdown' button, duh.
The normal shut-down process (which is different from the emergency shutdown) is also automatic. Flip the RUN/OFF toggle to OFF. The ECM then shuts off the fuel, turns on the "COOL DOWN" indicator light, and waits 5 seconds for the engine to spool down. After 5 seconds it turns ON the starter motor/blower to run cool air through the engine (kinda like letting your truck idle before shutting it off). It does that for 15 seconds. After 15 seconds passes it turns off the starter blower and waits another 3 seconds for the turbo to spool down. After 3 seconds it finally shuts off the oil pump and goes back to "standby" mode.
The emergency shutdown procedure basically just shuts everything down immediately. It simultaneously turns off the fuel and turns on the starter blower (to clear the combustion chamber so nothing explodes). Then 1 second later turns off the oil pump and starter blower. Its obviously not "good" for the engine to do an emergency shutdown because the oil pump is turned off right away, but if you blow an oil line, you cant do a "normal shutdown" procedure, because then the ECM would keep the oil pump running/spewing oil everywhere...
That is how everything works 'on the bench' and in my program/software/ECM simulator. I still have to finish up wiring the ECM to the jet engine and finish building the combustion chamber.
NOW...PHASE TWO of the jet engine rebuild, or "Jet engine version 3". This is way down the road...
Once I get "jet engine version 2" running properly and the auto-start system and ECM fine tuned, im going to convert it to electronic throttle control/fly-by-wire. Ill basically just hook up the throttle lever to a potentiometer that will send a signal to the ECM, and then the ECM will drive a little servo thats attached to the fuel valve.
When I eventually do convert the engine to electronic throttle control, Ill look into programing the ECM to monitor temps and stuff so when you push the throttle control to '100% power', the ECM will adjust the fueling a little bit to keep it from overspeeding or getting too hot. It will probably be a VERY VERY VERY basic feedback-loop system though. As far as I have figured right now, I think ill only be able to make it adjust the throttle in like 4 small steps "further open" or 4 steps "further closed", so it might surge a little bit, but who knows...
Also, the OBD port is bi-directional too so I theoretically might even be able to do some [very] basic data-logging like Turbine Inlet Temperature, Turbine Outlet Temperature, combustor pressure, throttle %, fuel pressure, and oil pressure with my laptop??? Maybe not though, I have no idea. I probably wont bother with that though...doesnt serve any purpose here on this scale other than the 'gee-whiz' factor.
Ill put up pictures of the new jet engine 'hard parts' in a little bit but here is a small portion of the ECM software/operating system programming.
Ben
My jet engine is getting a complete overhaul...
"jet engine version 2"
-New/bigger/redesigned combustion chamber
-New redesigned flame tube
-New redesigned fuel injector
-Airflow swirl inducer/evaporator mounted in the combustion chamber behind the fuel injector for better air/fuel mixing and to improve atomization. This also improves combustion efficiency and insures a more complete burn
-redesigned control panel/electronics
-redesigned oil cooler/fan
-new electric start system
-dual spark plug ignition system (my previous design only had 1 spark plug), basically it just uses the spark plugs for starting, think of them like glow plugs on a diesel engine
-BIGGER Garrett turbo off of a 12v71 detroit or something...I got it on ebay for cheap...this one has non-leaky seals and perfect bearings too. The old turbo had leaky seals and the bearings were shot which is why I retired "Ben Jet engine version 1"
With all of those improvements I decided I had to really step it up a notch in terms of engine control...
So I designed/programmed/built my own ECM.
This ECM is not some mess of resistors, timers, relays, and other ghetto'd stuff like the early analog car ECM's from the 70's-80's. It is a true fully-electronic digital ECM.
Its processor runs at blazing 8mhz, it has 128 bytes of RAM, and 4096 bytes of EEPROM. I wrote the entire operating system software from scratch. The current ECM OS is only about 1100 bytes so I have plenty of room left if I decide to add on more features or change stuff. My jet engine ECM is fully flashable, just like we can flash our dmax ECM's with EFILive.
Theres an "OBD" port on the board that I hook up to a USB port on my laptop and it takes about 5 seconds to reflash it.
Otherwise it is similar to a FADEC fly-by-wire system used on modern jet engines.
I can run it in "auto" mode, but I also have manual back up switches for the pilot injection, main injection, ignition, oil pump, and starter if I want to control everything completely manually. In addition to those manual-override switches, it also has:
-master power on/off
-auto-start button
-emergency shutdown button
-RUN/OFF toggle switch
The indicator lights on the new panel are:
-oil pump ON
-pilot injection ON
-main fuel injection ON
-ignition ON
-starter ON
-emergency shutdown light with a loud horn/buzzer
-MIL (yes, it has a check engine light!)
Gauges are:
-Turbine inlet temp (yes, its actually referred to as TIT)
-turbine outlet temp (TOT)
-combustor pressure (basically like 'boost')
-fuel pressure
-oil pressure
There are 3 "codes" it can throw:
-1 blink of the MIL/check engine light is low oil pressure (below 10psi anytime the engine is starting or running)
-2 blinks of the MIL is low combustor pressure (if its about to stall/flame out/whatever) (below 2psi when running)
-3 blinks of the MIL is high TIT (like the EGT gauge in our trucks, it sets a code if the temp gets above 1300*)
The AUTO START feature is probably my favorite. Generally, starting jet engines is a very tricky/critical procedure that almost requires 3 hands and a second set of eyes to watch all of the gauges.
All that will be required to start my engine is to first turn the 'master power' switch ON. When you turn the switch on, the ECM powers up and turns on all of the indicator lights/alarm for 3 seconds (just like your truck does when you start it). After the 'bulb test' is complete it goes into standby mode. Now you can start the engine manually with the manual-switches, or do the "AUTO-START". To auto-start the engine, just flip the OFF/RUN toggle to "RUN", and press and hold the start button for 5 seconds.
Once its in 'auto start' mode, it turns on the oil pressure and waits until it builds 35psi. Once the oil pressure is above 35psi it then turns on the starter motor (leaf blower that forces air into the cold side of the turbo) to spool up the engine. After 5 seconds of spool-up it turns on the ignition (spark plugs), and then the pilot injection (propane, its easier to light with a cold engine). After it turns on the propane it waits for the fuel to start burning. If proper light-off is not achieved within 5 seconds of turning the pilot injection on it cancels the start process and shuts down for safety. Once it sees the EGT/TIT go above 400* it determines that the engine has lit properly and waits for the combustion pressure (boost) to get above 3psi or so. Once the ECM sees the engine building boost it turns on the main fuel injection (diesel!!!). After it sees the EGT further rise above 600* or so and boost pressure get above 4 or 5 PSI, it turns off the spark plugs (because the engine is now self sustaining) and transitions to normal idle/running mode.
If at any time during the auto-start process the EGT goes above 1300*, oil pressure drops below 10psi, or the combustor PSI/boost goes below 2psi, it will turn on the check-engine light but it will still continue the start process.
IF during the auto-start sequence the boost pressure suddenly drops to zero psi, the oil pressure drops to zero psi, or the EGT continues to rise above 1400* and the engine starts to run away (called a hot start, jet engines can run away just like diesel engines), it immediately sounds the "emergency" alarm and automatically shuts down the engine.
Now that the engine is running properly you can use the throttle and speed the engine up/down/whatever.
When the engine is in normal running mode the ECM is monitoring EGT, boost, and oil pressure. If the oil pressure gets below 10psi, boost gets below 2psi, or the EGT goes above 1300*, it turns on the check engine light. If the 'driver' ignores the warning and the EGT gets above 1400*, oil pressure goes to zero, or the boost goes to zero, the ECM sounds the alarm and automatically emergency-shuts down the engine. You can also do an emergency shutdown by pressing the 'emergency shutdown' button, duh.
The normal shut-down process (which is different from the emergency shutdown) is also automatic. Flip the RUN/OFF toggle to OFF. The ECM then shuts off the fuel, turns on the "COOL DOWN" indicator light, and waits 5 seconds for the engine to spool down. After 5 seconds it turns ON the starter motor/blower to run cool air through the engine (kinda like letting your truck idle before shutting it off). It does that for 15 seconds. After 15 seconds passes it turns off the starter blower and waits another 3 seconds for the turbo to spool down. After 3 seconds it finally shuts off the oil pump and goes back to "standby" mode.
The emergency shutdown procedure basically just shuts everything down immediately. It simultaneously turns off the fuel and turns on the starter blower (to clear the combustion chamber so nothing explodes). Then 1 second later turns off the oil pump and starter blower. Its obviously not "good" for the engine to do an emergency shutdown because the oil pump is turned off right away, but if you blow an oil line, you cant do a "normal shutdown" procedure, because then the ECM would keep the oil pump running/spewing oil everywhere...
That is how everything works 'on the bench' and in my program/software/ECM simulator. I still have to finish up wiring the ECM to the jet engine and finish building the combustion chamber.
NOW...PHASE TWO of the jet engine rebuild, or "Jet engine version 3". This is way down the road...
Once I get "jet engine version 2" running properly and the auto-start system and ECM fine tuned, im going to convert it to electronic throttle control/fly-by-wire. Ill basically just hook up the throttle lever to a potentiometer that will send a signal to the ECM, and then the ECM will drive a little servo thats attached to the fuel valve.
When I eventually do convert the engine to electronic throttle control, Ill look into programing the ECM to monitor temps and stuff so when you push the throttle control to '100% power', the ECM will adjust the fueling a little bit to keep it from overspeeding or getting too hot. It will probably be a VERY VERY VERY basic feedback-loop system though. As far as I have figured right now, I think ill only be able to make it adjust the throttle in like 4 small steps "further open" or 4 steps "further closed", so it might surge a little bit, but who knows...
Also, the OBD port is bi-directional too so I theoretically might even be able to do some [very] basic data-logging like Turbine Inlet Temperature, Turbine Outlet Temperature, combustor pressure, throttle %, fuel pressure, and oil pressure with my laptop??? Maybe not though, I have no idea. I probably wont bother with that though...doesnt serve any purpose here on this scale other than the 'gee-whiz' factor.
Ill put up pictures of the new jet engine 'hard parts' in a little bit but here is a small portion of the ECM software/operating system programming.
Ben
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to give an example of how my little ECM compares to a duramax ECM, an LBZ duramax ECM has a 2 meg EEPROM (or 2,097,152 bytes), and I think a 66mhz processor??? The EFILive crew can correct me if Im wrong on that...
ben
ben
ben you are a nutcase lol btw i will excuse you for working on that since my parts delivery is not there yet....
There are two methods for producing/'extracting' actual shaft horsepower (torque) from a turbine engine.
The first one is the "free turbine". Sort of a separate "power recovery" turbine. The shaft that is connected to whatever you want to drive isnt actually physically attached to the compressor/turbine shaft. The separate driveshaft is attached to a separate turbine which is placed directly in the exhaust stream right after the gas producer's 'actual' turbine (the hot side of the turbo). The hot exhaust coming off the hot side of the turbine produces enough airflow that it then drives the separate 'power recovery' turbine before going out the exhaust pipe/into the atmosphere. Think of it like a torque converter in an automatic transmission I guess??? Except instead of using fluid to transfer 'torque' it uses extremely hot high pressure exhaust gasses to transmit torque. Thats the best way I can describe it.
the pratt&whitney PT6 is a 'free-turbine' type turboprop. This is probably the most common aircraft turboprop engine. If you've ever seen a turboprop-powered aircraft, theres probably a 7 out of 10 chance its PT6-powered.
If the engine was OFF and you walk up and turn the propeller with your hand, you arent actually "turning the engine". If you were SUPER strong, I guess you could theoretically grab the propeller when the engine is running and stop it from turning, and the "engine" (turbine/compressor/gas producer/combustion chamber) part would still be able to keep running. I think??????
In reality though (if you were super strong and stopped the prop from turning with the engine still running), a lot of back pressure would probably be produced (from the stopped/not-turning power-recovery turbine) and the actual "engine" (gas producer) part would experience some nasty compressor stalls and backfires...shortly after which internal temperatures would shoot through the roof and the engine would melt down. Thats just my guess though, im not about to walk up to an idling PT6 and arm wrestle it.
Now...the SECOND TYPE of turboprop (turboshaft) engine is the FIXED SHAFT type. The garrett TPE331 is probably the most common fixed turbine turboprop used on aircraft. The Allison T56/501 is another common fixed-shaft engine. Fixed-shaft turboprops are 'basic' in that they actually directly connec tthe prop to the "main" engine turbine/compressor shaft. Obviously though a gearbox though, as the main engine shaft spins at 30,000+rpm and props need to spin around 2,000.
fixed-shaft turboprops generally have a very NARROW rpm operating range due to the fact that the output shaft speed range is limited to the speeds that the main shaft must turn in order to support proper/efficent combustion and make the most possible power. Max RPM for a TPE331 might be 35,000 when the plane is taking off. When its at idle on the ground, it will probably still be at 33,000rpm or so. The main difference is fuel injected quantity and LOAD. Just like a diesel engine.
If you rev your engine to 3,000rpm in park it doesnt use very much fuel. Now pull up a long hill at 3,000rpm. Same RPM, but the load is greater so more fuel is required to produce the greater torque required to maintain that same 3,000rpm.The "throttle" on a turboprop engine is more like a "torque output" control than an "engine speed control" like you would think. To keep the engine operating at the same (efficent/proper) rpm under varied loads you vary the "torque output" (fuel rate).
The operating characteristics/physics of operation between a diesel engine and a turbine engine are incredibly similar...beleive it or not...
If you need a wide range of output speeds from a fixed-shaft turboshaft engine you must have some sort of clutch/variable drive on the output shaft. Then in addition, if you want that wide range of variable speed that is controllable by a "throttle lever", you must have a complex control module that can vary the clutch/transmission/variable drive output SPEED/RPM in proportion to actual fuel rate...in order to maintain a CONSTANT turbine/mainshaft RPM regardless of load/OUTPUT speed.
The only way you could use a fixed-shaft turbine engine on a wheeled vehicle/go-cart would be to use a CVT [transmission]. You could not use a standard automatic, manual trans, or centrifugal clutch with a fixed-shaft turbine engine (because those types of trannys depend on the engine running throughout a wide RPM range) on a wheeled car.
Free-turbine engines are more forgiving with shaft output speed and can run at a wider range of speeds and can tolerate speed changes in the output speed (say, the wheels of the car its driving) because for the most part, the main "engine" part is going to be spinning at its own constant RPM . Remember the "torque converter" analogy that I mentioned earlier. SO what this means is that in my opinion, on a go-cart or something simple, its really not feasible to operate the engine like a fixed shaft engine because if you suddenly start going up a hill or the load/speed of the wheels/axle changes rapidly you can risk disrupting the "steady running state" of the engine.
SO......when/if I put it on a gocart, Ill find another turbo to use as a "power recovery turbine" and then just route the exhaust gases out of the main/primary gas producer "engine" into the inlet of the HOT SIDE of the second turbo. THEN ill connect a gearbox/shaft to that second "passive" turbo and voila I have a [free-turbine style] turboshaft engine.
The two types each have their own distinctive sound too. Fixed-shaft turboprops have a very shrill raspy shriek/whistle/whine at idle. Free-turbine turboprops have a much smoother softer lower pitched whistle without that raspy dentist-drill noise. The best way to describe them is fixed-shaft turboprops sound like a CHEETAH turbo and free-turbine turboprops sound like MPI Twins.
If that makes sense? Sorry, im rambling.
ben
(if any of that is wrong, anyone feel free to correct me...im not copying/pasting crap from google or wikipedia, that above stuff is just off the top of my head so I could very well have accidentally mixed things up/forgotten things)
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It is nice to see people doing homemade digital engine controls. :thumb: Make sure you get a less tentative friend to get the next video :spit:
Would you be able to put a shaft speed sensor on the turbo and have the engine computer compensate for changing loads (and therefore shaft speed) of, say, an alternator as different electrical demands were placed on the system? I'm not sure how quickly the shaft speed would change as the loads were changed, but if the turbo didn't immediately stall/flame out, even a 8MHz chip should do OK. Plus, from what I saw in the screenshot, it looks like your code is fairly efficient.
Although, adding shaft speed control would add another layer of complexity that isn't needed for your current plans.
Subscribed, this is good stuff!
Would you be able to put a shaft speed sensor on the turbo and have the engine computer compensate for changing loads (and therefore shaft speed) of, say, an alternator as different electrical demands were placed on the system? I'm not sure how quickly the shaft speed would change as the loads were changed, but if the turbo didn't immediately stall/flame out, even a 8MHz chip should do OK. Plus, from what I saw in the screenshot, it looks like your code is fairly efficient.
Although, adding shaft speed control would add another layer of complexity that isn't needed for your current plans.
Subscribed, this is good stuff!
Just when you think Ben can't get any cooler, he ups the bar....
I'd love to see that thing in action...
I'd love to see that thing in action...
Im trying to figure out also if I want to/need to rig up a sort of "condition" control/lever.
airplane turboprop engines have a control called "condition". Its a lever and sits right next to the 'throttle'. I guess its sort of but sort of not the equivilent to the "mixture" control on a piston engine. Maybe think of it as more like a "high" and "low" pressure/flow setting for the fuel injection pump/system. Mainly you just move it between three detents, fuel cutoff, 'low idle' and 'high idle'. Of course, like diesel engines, turbine engines have a unrestricted air intake (no throttle plate). Some bigger turboprops can gulp 100lbs or more of air per SECOND. I bet a dmax MAF sensor would have fun measuring that.
another fun fact, if you are ever looking in the cockpit of a turboprop airplane/commuter airliner, you can tell right away if it has FREE-POWER or FIXED-SHAFT turboprop engines. Airplanes with free-power turboprops (like the pratt&whitneys) have three sets of big levers in the middle of the cockpit....
-throttle (or more accurately torque/power output setting) on the left
-propeller rpm (controls the pitch of the blades because you want different pitches on takeoff and cruise, think of it like low gear and high gear on a car transmission) levers in the middle
-condition levers on the right
If the airplane has fixed-shaft turboprops (garrett, allison, rolls royce), there will only be TWO sets of levers
-throttle (power output/torque) on the left
-condition on the right.
there isnt a propeller RPM/pitch control on fixed-shaft engines because its set automatically in a very specifically-calculated proportion to the torque/power setting that the pilot sets. Because if you kept torque/power constant and varied the prop rpm/pitch/load separately you could drastically shift the RPM of the main engine (because remember on a fixed-shaft engine, the prop is actually directly connected to the "actual main engine") and cause lots of problems. Sort of like if you tried to shift your dmax into 5th gear going up a hill at 30mph. Bad bad...
airplane turboprop engines have a control called "condition". Its a lever and sits right next to the 'throttle'. I guess its sort of but sort of not the equivilent to the "mixture" control on a piston engine. Maybe think of it as more like a "high" and "low" pressure/flow setting for the fuel injection pump/system. Mainly you just move it between three detents, fuel cutoff, 'low idle' and 'high idle'. Of course, like diesel engines, turbine engines have a unrestricted air intake (no throttle plate). Some bigger turboprops can gulp 100lbs or more of air per SECOND. I bet a dmax MAF sensor would have fun measuring that.
another fun fact, if you are ever looking in the cockpit of a turboprop airplane/commuter airliner, you can tell right away if it has FREE-POWER or FIXED-SHAFT turboprop engines. Airplanes with free-power turboprops (like the pratt&whitneys) have three sets of big levers in the middle of the cockpit....
-throttle (or more accurately torque/power output setting) on the left
-propeller rpm (controls the pitch of the blades because you want different pitches on takeoff and cruise, think of it like low gear and high gear on a car transmission) levers in the middle
-condition levers on the right
If the airplane has fixed-shaft turboprops (garrett, allison, rolls royce), there will only be TWO sets of levers
-throttle (power output/torque) on the left
-condition on the right.
there isnt a propeller RPM/pitch control on fixed-shaft engines because its set automatically in a very specifically-calculated proportion to the torque/power setting that the pilot sets. Because if you kept torque/power constant and varied the prop rpm/pitch/load separately you could drastically shift the RPM of the main engine (because remember on a fixed-shaft engine, the prop is actually directly connected to the "actual main engine") and cause lots of problems. Sort of like if you tried to shift your dmax into 5th gear going up a hill at 30mph. Bad bad...
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You built that at 14? :thumb: Very cool, Ben.
Yep, you should be a mechanical engineer.
Yep, you should be a mechanical engineer.
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I was either 14 or 15, I forget. As far as mech. engineering, I wouldnt have made it past the first 2 years (the book work; unfortunately you dont actually do anything fun in the first two years of getting an ME degree). I have several good friends who got engineering degrees at an engineering school (clarkson university) close to my [liberal arts] school (st lawrence university). I was over there a bunch cause there was a shop where we would all work on our trucks and stuff. As a whole, that campus was miserable, nobody looked happy to be there, not many girls, everyone walks around with their head down, buncha robots. But thats kinda the way engineering schools tend to be. Any of you guys who know me in real life know that I am anything BUT serious/non-energetic haha.
I like building stuff and if I can figure things out if I can 'apply' the concept at hand to something real life. But forget the hard core math and stuff that isnt tangable/applicable to a real life machine... As strange as it may seem, (given how technical I am with the truck stuff) I dont regret not doing an engineering degree (when I was in college) at all.
Whenever im building a project that requires 'actual' engineering-type stuff, I just get a book on it and try to teach myself. Sometimes it works, sometimes it doesnt and the thing I build ends up blowing up. :joker:
ben
BTW Tom sorry I missed your call earlier, Ill give you a call back tomorrow:
As far as mech. engineering, I wouldnt have made it past the first 2 years (the book work; unfortunately you dont actually do anything fun in the first two years of getting an ME degree). I have several good friends who got engineering degrees at an engineering school (clarkson university) close to my [liberal arts] school (st lawrence university). I was over there a bunch cause there was a shop where we would all work on our trucks and stuff. As a whole, that campus was miserable, nobody looked happy to be there, not many girls, everyone walks around with their head down, buncha robots. But thats kinda the way engineering schools tend to be. Any of you guys who know me in real life know that I am anything BUT serious/non-energetic haha.I like building stuff and if I can figure things out if I can 'apply' the concept at hand to something real life. But forget the hard core math and stuff that isnt tangable/applicable to a real life machine... As strange as it may seem, (given how technical I am with the truck stuff) I dont regret not doing an engineering degree (when I was in college) at all.
Whenever im building a project that requires 'actual' engineering-type stuff, I just get a book on it and try to teach myself. Sometimes it works, sometimes it doesnt and the thing I build ends up blowing up. :joker:
ben
BTW Tom sorry I missed your call earlier, Ill give you a call back tomorrow
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Learned something new from all that, Ben. Didn't know about fixed and free power types of turbo props. That explains why a C-130 taking off never sounds like the turbo props wind up. You can hear the pitch of the engine change but no huge spool up.
Cool.
Cool.
This is the only turboprop plane I ever really knew much about:
http://www.hermantheduck.org/pages/aircraft section pages/cv580.html
Good Ole' North Central Air. You knew when one of those Convairs was coming. Very distinctive sound.
http://www.hermantheduck.org/pages/aircraft section pages/cv580.html
Good Ole' North Central Air. You knew when one of those Convairs was coming. Very distinctive sound.