Aircraft in aces high II

[Bronk]

Ok now I am confused? What produces thrust or in this case more thrust if not the engine??  I are NOT an engineer

Prop pitch ?

[phatzo]

and torque

[Kazaa]

"1kg object needs 3 times its weight to counteract gravity."

[MoJoRiZn]

and torque

wouldn't that be only static thrust against the fuselage of the aircraft?  not a type of thrust that would actualy help the aircraft, yet a type of thrust that the propeller would have to overcome to move forward?

[hitech]

Boxboy in physics terms you have a few concepts.

Force I assume you know, this is measured in pounds or newtons. Thrust is a force.

Work is = Force * Distance.

Power = Work / Time.

Speed =   Distance / Time.

Solving these equations we also get

Power = force * speed.


So in airplane terms lets ignore drag for a sec.

Once an airplane is accelerated to flying speed it requires no force to continue flying but the plane is still generating lift and hence requires no power to continue flying level but is still generating lift. Now picture a helicopter with no drag, once the rotors are accelerated they would continue to provide thrust/lift with out any power.

Now with drag and flying level all power is simply used in overcoming drag. Power required is force (i.e. drag) * speed.


But the key is the power definition. of Force * speed.

So now to calculate power for climb speed we simply need the weight of object and speed of climb to calculate power required. I.E. Power = Weight * speed.
Horse powers definition is Lifting 550 pounds 1 foot in 1 sec.
But if we put in a gear box or lever we could be lifting 1100 lbs 1 foot in 2 secs with the exact same power.

So angle of climb is all about a propeller and plane design. A helicopter climbing straight up requires no more extra power then an airplane with the same weight  if they climb at the same rate.

So to summarize why i pointed the thrust / power out. Not to many engineers would substitute the word power for force when describing what is required for angle of climb.

HiTech
 

[LLogann]

Don't forget Engine Dynamics young man!!!! 


WOW, you're going to get blasted, if you haven't already. 

Time to read the replies......   

[gyrene81]

Anyone want to make a bet that the "aircraft engineer" OP doesn't post a reply until after school is out and he's finished with dinner/homework?

[LLogann]

Actually.....  Rereading him, he states "airframe engineer" but also made it two words..........   

Anyone want to make a bet that the "aircraft engineer" OP doesn't post a reply until after school is out and he's finished with dinner/homework?

[AKH]

Engineer must be one of the most abused terms of the last century.  Do anything slightly technical and you have an instant right to call yourself an engineer.



TV repairman? No - he's a TV engineer!

[gyrene81]

Sanitation Engineer

[WMLute]

Actually.....  Rereading him, he states "airframe engineer" but also made it two words..........   

yeah, I caught that too.

when "pretending" to be something, it really helps if you spell it correctly.

[dtango]

I understand what BulletVI is trying to say though it would help if he provided more specificity (yes that's a word!).  HT's responses to BulletVI, I can understand because HT know's what he's talking about.  Some of you guys piling on however ....hmmmm .

BulletVI:

Your answer lies in understanding the following relationships and as they change with respect to time.

For an ACCELERATED climb (forward airspeed not constant) the forces along the direction of flight can be expressed as:

F = Thrust – Drag – Weight * sin (climb_angle)

Since weight = mass * gravity we can subsitute in the equation above thus becoming

F = Thrust - Drag - Mass * gravity * sin(climb_angle)

In your Tempest, A6M, Spit8 example you were focused on the effect of gravity.  The greater the climb_angle, the greater the effect of weight / gravity on the overall forces.  But that's only one of variables.  Thrust and Drag play a part as well.  Ignore them at your peril .  Be very careful of oversimplifying the dynamics because it will bite you in the butt.

Another way to look at an accelerated climb is this..

Specific Excess Power (Ps) = (T - D) / W * V = (change_in_alt + change_in_airspeed)

Hope that gets you on your way to understanding!

Tango
412th FS Braunco Mustangs

[Boxboy]

Thanks Hitech for clearing that up, it has been a long time since I really thought about math problems and such.  I completely forgot about levers, pullys, and such and their effect on things for the same effort.

[SlapShot]

Hope that gets you on your way to understanding!

I strongly doubt it.

[redcatcherb412]

All I know is no matter what plane I pick, I never can climb up fast enough to an enemy before he gets me in his dive, or catch up to bombers. Stall it every time. Course I wuz a ground grunt so flying the planes is just plain fun for me.