Wednesday, April 29, 2015

How things work?

I realized many people don't really know how things work. So, I decided to try to give people a shorthand knowledge of things like Gasoline reciprocating engines and Diesel Engines and stuff like that.

Note: I realized a day later after writing about Gasoline engines and Diesel engines that I am making the assumption that they are in Cars and Trucks. However,  these engines can also be in boats, lawn mowers, model air planes etc. as well as planes of various sizes as well regarding gasoline engines. In boats usually you have some sort of flywheel starting them too. or in smaller engines you might be starting with a pull cord or in a model airplane by priming the propeller. So, I'm mostly assuming we are talking about cars and trucks below in gasoline engines. end note.

Gasoline engines: They are turned on by being started with an electric starter which spins the flywheel. If there is gas in the carburetor or the fuel injection system(most cars are now fuel injected now in order to conserve more gasoline, so most don't have carburetors anymore. So, if there is gas in the Carburetor or Fuel injection system and if there is an electric spark in the spark plug when the electric starter motor spins the flywheel often the engine will start if all conditions are right. Then the spark plugs keep sparking in sequence now usually programmed digitally rather than by using a distributor cap and points like in the old days. When you put your foot on the accelerator more gas runs through the fuel injection system or the carburetor and the engine speeds up. Then the power is transferred to the transmission if the car is in Drive it moves forward or in Reverse it moves backwards. Or if you have a manual transmission it won't move forward or backwards until you engage the clutch. However, with a manual transmission you have to shift gears to move faster to get out of first gear which on most cars only goes up to 20 to 25 miles per hour without blowing up the engine by taking it into the red. So, it is easier to drive an automatic transmission car than a manual shift.

diesel engine:

The diesel engine does not have spark plugs. Instead diesel oil is literally an oil that explodes when compressed. So, the same starter motor starts the engine spinning and often there is a glow plug to preheat the cylinders to make the diesel oil explode better. So, especially if it is cold outside it is harder to start a diesel engine. So, once they get their diesels started often truckers don't turn off their engines until they reach their destination even if it is all across the nation from  California all the way to a place like New York.

So, the starter motor spins the engine through the flywheel and as the diesel engine engages it has a lot more power than a gasoline engine. However, because of higher compression ratios the engines have to be much stronger built than a gasoline engine. Also, diesel tends to have more pulling power than a gasoline engine which is why often trucks are diesel engines. Also they tend to burn less fuel than Gasoline engines so they tend to get better mileage than gasoline engines. However, often diesels are smelly and loud and the smell of diesel makes a lot of people sick when it is burned.

So, diesel engines once they get started are actually generally more reliable than gasoline engines. But, they had a hard time building small Diesel engines until the Europeans started building great and not smelly diesels. So, it is hard for me to understand why diesel taxis and cars haven't caught on here more because the Europeans have really got auto diesels down.

Jet engines:

There are mostly two types of Jet engines that are used now. They are the prop jet (or propeller jet) and the (Fan jet)

I'm less clear about how a prop jet works even though I just flew last week on a Bombadier on Alaska Air Lines from Medford, Oregon to Portland Oregon.

The prop jet on the Bombadier had about 12 blades it looked like. The general Idea with a prop jet is to start out with the jet operating the propeller and the propeller increases the wind into the jet behind the propeller so it works more efficiently. Prop jets generally fly at slower speed than Ram or Fan jets fly at. So, they need at slower speeds the increased flow of air from the props to make the jet work more efficiently.

The jets most airliners use for 400 to 600 mph flight are usually fan jets or ram jets. They run on a form of kerosene specially blended for this kind of use. When a jet is first starting up by squirting jet fuel kerosene and starting a kind of rocket reaction so flame might come out of the back of the jets or smoke when they are first started up and the internal rotors start spinning and then more and more air is sucked into the front of the intake of the jet it is at first a lot like a rocket engine starting up. But, once the internal rotors start spinning at higher and higher speeds and more and more kerosene increases the burn rate and sucking more and more air in the thrust increases more and more. Then the pilot tests the engines to make sure they are going to be functional for the whole trip, especially if this is across ocean with no airports to land at in an emergency. The kerosene is stored in the wing tanks for long flights. So, when there is an emergency the pilot jets extra fuel when necessary if there is time before crash landings so the whole plane doesn't explode from all the kerosene if it is still in the wings. You don't want to crash land with full kerosene tanks or everyone is sure to die in the plane. So, if there is an emergency pilots either burn or jetison fuel before landing to save lives whenever possible.

1 comment:

Anonymous said...

Fred, tell us how powdered water works! GG