#garfield Logs

Oct 11 2012

08:45 rue_house wouldn't it go off too early?
15:12 any79939103 only if it was hot enough to
15:13 any79939103 the interesting part is, if it were injected starting at the point in time it is to ignite, and the sparj fired at the same time, and the propane was at enough pressure, the injector would think it was firing into a rocket combustion chamber
15:15 any79939103 the intereasting gotcha becomes: before detoation, the pressure may be only 150psi, but during detonation the pressure may be 600psi, so can the injector push the full load of propane in at one time, in time, before the end of useful piston stroke?
15:16 any79939103 i am thinking that if gaseous propane is what's being pushed, the answer is "no", but if a liquid is pushed yeas, but as usual there is a gotcha: the liquid propane cannot burn, it will cool the fire to get heat to vaporise and disperse into the air in the chamber so it can burn
15:17 any79939103 cooling the detonation does two things: reduces cyl pressure (torque) and slows the fire (like spraying steam into it)
19:43 katsmeow-afk rue, a 28" dia tire turns at the same mph as it's rpm
19:44 katsmeow-afk so a steam engine geared str8 to the rear tires will be turning only 80rpm at 80mph
19:45 katsmeow-afk now, how much foot-lbs torque do i need on the rear axle to carry a 10,000 lb load up a 20 degree slope at 80mph?
20:38 rue_house 80mph has nothing to do with it...
20:39 rue_house you split the normal into components of the directional forces
20:39 rue_house hmmm
20:58 katsmeow-afk what??
20:59 katsmeow-afk 80mph in this case = 80rpm
21:00 katsmeow-afk if i assume 200hp = 400ft-lbs at 2200 rpm, then 80rpm @200hp = 11,000 ft-lbs
21:01 katsmeow-afk obviously, coupling 11,000 ft-lbs to a moving axle in a moving truck is tricky, so using the 3.5:1 differential, the input to the diff is 3,142 ft-lbs at 280 rpm
21:02 katsmeow-afk which is stll an easy target to hit with direct drive steam
21:02 katsmeow-afk using another gear set to lower the driveshaft torque some more wouldn'
21:03 katsmeow-afk t change the driveshaft torque
21:04 katsmeow-afk it would make it cheaper to make the steam engine, maybe, to lower it another 3.5:1 , so the engine turns 1000rpm and puts out 900 ft-lbs
21:04 katsmeow-afk 1000 rpm is the high end of what i feel comfy with
21:06 katsmeow-afk hmm 11,000 ft-lbs @ 80 rpm is onlt 168 hp
21:06 katsmeow-afk anyhow, 200hp is too low
21:08 katsmeow-afk 300hp = 19,700 ft-lbs @ 80 rpm , i am pretty sure the regular truck tires would shred
22:05 katsmeow-afk 19,000 ft-lbs sounds high, but at 500 psi it's the push that a 7" piston would deliver
22:07 katsmeow-afk so roughly speaking, a steam engine at 500psi with two 7" double-acting cylinders, turning only 1.3 turns per sec, would deliver 300hp
22:09 katsmeow-afk that's with 1ft crank throws
22:10 katsmeow-afk which shouldn't be any problem at only 80 rpm
22:10 katsmeow-afk or, use 4 double-acting cyl and shorten the crank arm to only 6 inches
22:13 katsmeow-afk course, you need to make it bigger to accomplish efficency
22:15 rue_house I dont know what the component of 10000lb is at 20 degrees
22:15 katsmeow-afk oh
22:15 rue_house it requires advanced thinking I cant get up to just now
22:15 katsmeow-afk well, at 90 degrees it's 10,000 lbs
22:16 katsmeow-afk so lets say at 45 it's 1/2 that, and go from there
22:16 katsmeow-afk 111 per drgree
22:16 katsmeow-afk so 20 degrees would be 2,200 lbs
22:20 katsmeow-afk i wonder why they need 200 - 300 hp engines to pull 5 tons that need only 2,200 lbs of pull,,,,,, ohhhh, with a 28" dia tire, the ft-lbs also equals the pull force
22:21 katsmeow-afk 2,200 lbs at 80 rpm = 33 hp
22:21 katsmeow-afk wtf
22:22 katsmeow-afk someone broke the math