Need Ki84 HAYATE's data!

[Steven Que]

Hello guys.
I need some schematics for Ki84 hayate
or cutaways.
These picture and datas will help me to do report of aircraft.

Thanks.

 

[Shinpachi]

Hi Steven Que!

You have posted three times for a question in half an hour.
What kind of report are you going to do in a so hurry?
I'm very curious. You will be able to get the necessary data from here -

Airwar.ru(1)
Airwar.ru(2)

Good luck!

 

[Micdrow]

Hello guys.
I need some schematics for Ki84 hayate
or cutaways.
These picture and datas will help me to do report of aircraft.

Thanks.

I have this that may be of some help.

 

[Steven Que]

Thanks guys.
My report is analyse the aircraft's stability.
Then I choose Ki84 to analyse
then tell the aurcraft is good at stability or not.(most craft is stability)

I like these picture

oh! I forget that!
What is the scale of these picture?

 

[Shinpachi]

What a great report you are doing!
I want to know the result if Hayate was stable or not.

The scale depends on the size you draw or print on the paper.
You can calculate it refering to the list Micdrow shows or the list attached here if it's meteric system.

Thanks.

 

[Ivan1GFP]

Additional Information.

- Ivan.

 

[Steven Que]

Hmm...
These data is the part of I need
But I need the data from aerodynamic's concept now
Center of gravity's location
Aerodynamic center on the wings
Then I can use equations to analyse
Maybe need the airfoil's code to find that(maybe NACA 4,5,6 digit)
Thanks

 

[Ivan1GFP]

I would have figured that is ALL the data that you would need from the start. I am somewhat surprised that it took this long to make this particular request. Unfortunately, the only folks I can think of that would have this information would be the folks that rebuilt the only existing Ki-84 that was sold back to a private Japanese buyer or the folks at Wright Patterson or TAIC who tested the aircraft when it was captured or perhaps the Japanese private owner of the only existing aircraft. I am guessing that if you are lucky, you will find some pilot's reports of the captured aircraft. Actually finding the weights and balances manuals and other such data would be great. If you do, please share.

- Ivan.

 

[Vincenzo]

would be usefull to know the speed at which power setting it's obtained

 

[Shinpachi]

8)

 

[MacArther]

Micdrow, where do you and other people get these awesome technical listings? All the books I have just list the standard "Weight, maximum weight, maximum speed, cruising speed, armament, number produced...etc." None of them go into wing loading or any of that other stuff on there....

 

[Ivan1GFP]

Hello MacArther,
I have no idea where folks are coming up with some of the more esoteric data. Wing Loading is no great information. It is easy to calculate once you have other commonly available figures. The table I posted was just something I found online. I should scan and post the marked up copy that my wife translated for me because I believe the only person who can read it at the moment is Shinpachi.

Hello Shinpachi,
How did you get the Center of Gravity? Is it via observation of the wing planform and the likely center of lift as I am reading from your projections of the leading and trailing edges?

- Ivan.

 

[Shinpachi]

Hi Ivan1GFP!

The center of gravity is(or was) always on the main spar.
To get the MAC location, I simply obeyed aviation basics.

In order to get informations, I only rush into the data mountain like Kamikaze(or Micdrow)!
Cheers everyone!

PS: New design of this forum is sophisticated and good.
I like it.

 

[Ivan1GFP]

Hello Shinpachi,

I am thinking that the CoG on the Main Spar is something that can not be assumed about various aircraft designs. It may be optimal and intended in the original design, but a lot will depend on the disposable loads that are carried or any design or equipment changes.

The P-51 and P-39 are two cases where CoG changes pretty seriously depending on the load.

- Ivan.

 

[Shinpachi]

Thanks Ivan1GFP for your comment about the center of gravity.
Yes, I know it is too rough to say every main spar is on the center of gravity as it depends on the wing design. Sorry for my so simple explanation last time.

Some operation manuals for the old Japanese fighters say "Main spar(exactly forward spar) supports the whole weight of the aircraft" and, in fact, the center line of fuselage and the main spar crosses on the center of gravity. I think the center would be an average point of fully-loaded and empty conditions though I find no exact explanation about it yet.

 

[MacArther]

You have to calculate stuff???? Eh, I think I'll stick to minimum specs and whatnot, I'm no good at math.

 

[Ivan1GFP]

Hello MacArther,
Wing loading is simple: Weight of Aircraft divided by Wing Area. If someone is quoting a wing loading value, they got the value at ONE specific aircraft weight which may not be the one you are interested in. A value that was arrived at with the aircraft's maximum take-off weight is worthless to me if I am interested in performance in "air superiority" configuration with half internal fuel and no external stores.

Hello Shinpachi,
Please take a look over at the J2M Raiden thread. Perhaps you have information there?
I believe your methods are a pretty good estimates if the information truly isn't available, but because they are "reasonable" values, any analysis based on them will only yield "reasonable" results. The only way I can see of getting real data is to either find the documentation in some aircraft manual or test results, or by getting the owner of one of these planes to put the thing up on scales and calculate the CoG by the weights on each wheel with the plane in a known loading condition.
This is why I was somewhat surprised at the choice of such an obscure subject to analyse for stability. Just about any US fighter has enough documentation that is freely available and even then, folks sometimes get things very wrong.
I am not quite sure I understand your comment about the mainspar and fuselage centerline. Are you saying that the vertical CoG is at the junction of the mainspar with the fuselage? If so, then my "intuitive" feeling (which isn't worth much) is that this may not be correct. There isn't anything heavy below the mainspar centerline, but there is LOTS of heavy stuff such as the majority of the aircraft structure (fuselage and wings), engine, pilot, fuel, landing gear, etc that is either aligned vertically with the mainspar or well above it.

- Ivan.

 

[Steven Que]

8)

Hmm~Looks so great
I know the aerodynamic center is at 0.25 camber of the airfioil
many points link into a line(red line) is straight
But...not 90 degree with the axis of fuselage
are you sure the gravity of center is at the 0.25 camber of the airfoil of wing's root?

I ever think if aircraft take off,tail will be raised before.
Then use some simulator software to find out the moment that tail raised.
And record the angle of fuselage axis with horizontal line,speed of taxi.
solution of the moment balanced equations may find out the center of gravity.

If your picture show the center is correct
I would doing that easily
Because I can use flying simulator to do another way.
I want to show the Ki-84 combat with P-51D would excited for me
Indeed Ki-84 ever won the battle with P-51D in history.8)

Now here is a data is confuse me still
the airfoil's shape...
I ever tried to find the picture with airfoil's shape
or data of airfoil(like code NACA 4,5,6 digit)
and find out the Lift coefficient to analyse
That is one of the important data

 

[Steven Que]

OK guys
Maybe judge the issue that how to know the data or get it is difficulty
Then I have some idea with these data they give me.

====find out aerodynamic center====
Assume the fuselage is not mention with whole aircraft's aerodynamic center
(Actually it is not true for real aircraft)
then just know the main wing and tail horizontail wing's data
Assume the tail horizontail wing have no lift at 0 degree angle of attack when flying.
for Ki-84's main wing,leading edge's line is vertical with axis with fuselage axis.(from top view of aircraft)
Then 0.25 camber's line is not vertical with fuselage axis(from top view of aircraft)
Use the equation of lift L=QSCl
L=Lift, Q=0.5*(mass(air)/volume(air))*velocity(m/s)^2, Cl=coefficient of lift
Find out the center of lift on the line of 0.25 camber at left and right wing.
Then two centers will be a vertical line with fuselage=>the point may the aerodynamic center

====center of gravity====
It is difficult to me to find out the COG
Because no manual and no correct data that I can use
ever tried to buy a good model with correct scale of weight.(too expansive!! may not find the model now)
Then I think...
When I play flying simulator. I saw the aircraft's tail would be raised before aircraft leaving ground.
"The moment with COG on fiselage axis and lift on the aerodynamic center must be balanced" I think
So before I record the moment that tail raised's data(speed of taxi,angle of attack)
I have to know the weight of aircraft(include weight of loading)
then calculate lift with area,speed get the lift
the gear on the ground will be a useful data(from side view of aircraft)
Then solve the equation of force. the COG may find out.
==================

good idea? or stupied?

hmm~I still need airfoil's shape or data...

 

[Shinpachi]

Hi, Ivan1GFP!
Thanks for your good and kind explanation about the center of gravity.
I fully understand you are a very expert of aerodynamics.
However, please let me go on my own way for the time being as I find no remarkable reason enough to change my opinion yet.

Hi, Steven Que!
Attached image shows my answer at the moment though this is simply a reference for you.
37.7% is very reasonable because Ki-84 was famous for its super high maneuverability with the high powered engine at the initial stage of development. To prevent the disintegration in mid-air, the control stick was designed shorter than Ki-43 because even Ki-43 with the less powered engine often caused the disintegration.

As a result, Ki-84 was not so popular as Ki-43 with the pilots.

Airfoil.
I believe here is an answer for you...
http://www.ww2aircraft.net/forum/flight-test-data/need-ki84-hayates-data-18058.html#post493515