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Sturgeon's House

Xoon

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  1. Tank You
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    So it levitates on a cushion of gas? 
     
    I read something about it on the War Thunder forum that it used bearings. 
    Is the gas used for counteracting the rotation? 
     
     
     
     
    Page 7 SH_MM talks about liquids in armor. The only time I know the forum talked about it. 
     
    Bronez also links a document:
    http://onlinelibrary.wiley.com/doi/10.1002/prep.201500137/full
  2. Funny
    Xoon got a reaction from Zyklon in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  3. Metal
    Xoon reacted to Lord_James in Competition: Californium 2250   
    Now that it doesn’t feel like I have an ice pick slowly being pushed into my head, I can elaborate. 
     
    My engine is closer to the Nomad 2, except the axial compressor is literally the super and turbo chargers. After the compressor, it splits into the ignition air ducts and cooling air ducts. After the cooling air ducts make their way through the engine, they reconnect to the exhaust, then go through the power recovery turbines. 
     
    The supercharger is used at all speeds, and instead of disconnecting at high speeds, it “shifts down a gear” and acts as a second compressor stage to the turbo. 
     
     
    I might have mixed up dual clutch and CVTs, but yes I want a CVT. 
     
    I think I’m going to have 5 gears: 
    continuous forward, high torque forwards, neutral, high torque backwards, continuous backwards. 
     
     
     
  4. Funny
    Xoon got a reaction from Toxn in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  5. Funny
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  6. Funny
    Xoon got a reaction from That_Baka in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  7. Funny
    Xoon got a reaction from LoooSeR in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  8. Funny
    Xoon got a reaction from N-L-M in Competition: Californium 2250   
    Pfft, of course not, who would want to squeeze more power out of  it? he he
     
    * discreetly crumples paper and throws in trash*
  9. Tank You
    Xoon reacted to Kal in Competition: Californium 2250   
    Re Mg vs Al for welding.
     
    The Mg is easier for fine welding like bikes and lightweight structures, but is unsuitable for thick welds.  Mg welding uses only about 40% of the heat for the same thickness as. Al welding but is unsuitable for deep penetrating welds because the Mg boiling point is a lot lower than Al boiling point.  (Even though the melting points are almost the same.)
     
    Al obviously conducts heat away from the weld a lot faster than Mg.
  10. Metal
    Xoon got a reaction from Zyklon in Competition: Californium 2250   
    I think I am done with my suspension, for now:

     
    It comes out at roughly 350 kilograms. I would say probably closer to 400kg though. 
     
     
     
    On the hull:

  11. Metal
    Xoon got a reaction from Collimatrix in Competition: Californium 2250   
    I think I am done with my suspension, for now:

     
    It comes out at roughly 350 kilograms. I would say probably closer to 400kg though. 
     
     
     
    On the hull:

  12. Metal
    Xoon got a reaction from N-L-M in Competition: Californium 2250   
    I think I am done with my suspension, for now:

     
    It comes out at roughly 350 kilograms. I would say probably closer to 400kg though. 
     
     
     
    On the hull:

  13. Metal
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    I think I am done with my suspension, for now:

     
    It comes out at roughly 350 kilograms. I would say probably closer to 400kg though. 
     
     
     
    On the hull:

  14. Metal
    Xoon reacted to N-L-M in Competition: Californium 2250   
    @Lord_James
    Alright people, it's time for M A T H. For convenience's sake, all the units in this post are going to be SI, MKS.
    Today's episode: external ballistics and differential equations!
    So, we know that the force of drag is roughly proportional to the velocity squared (not entirely true, but we'll get back to that later).
    Drag equations take the following form:

    Where Rho is the air density, a is the reference area of the projectile (for shells and rockets, the convention is that the reference area is the cross sectional area of the projo), and Cd is a dimensionless drag coefficient.
    Additionally, we know from Newton's second law that F=m*a, which can be rejiggered to a=F/m.
    And we know that acceleration is by definition the derivative of velocity by time.
    Combining the above, we get the following differential equation:

    Where m is the projectile mass.
    Solving this diff eq, (and the one for velocity being the time-derivative of speed), we get:

    Where x0 and v0 are the initial position and velocity, and ln is the natural logarithm.
    We now have almost everything we need, but where are we going to get drag coefficients for 155mm shells at this time of day?
    Why, DTIC of course!
    DTIC has helpfully provided the complete measured drag curve for the shell,155mm, HE, M101 (The precursor to the M107, with different driving bands but otherwise identical): https://apps.dtic.mil/dtic/tr/fulltext/u2/209134.pdf
    Consulting the graph so helpfully provided, we note something odd about our previous assumption:

    The drag coefficient isn't a nice constant value, but instead varies with velocity! this is an outrage!
    Except it only varies fairly mildly, so we can assume it to be quasi-constant, and we don't have to solve the diff eq for a velocity-dependent Cd (or Kd in the DTIC paper).
    So assuming a M101 equivalent shell, launched at 800m/s, a Cd of 0.1 seems reasonable. Solving the above equations with the following constants:

    I suggest shoving the above values and the equations found for velocity and range into Excel, and solving both by t, before observing the velocity as a function of range.
     
    We get that for a range of 3000m, we have a ToF of 3.86 sec, at the end of which we have a terminal velocity of 755 m/s - A fairly significant residual velocity, I think you'll agree.
    We then go on to note that throughout the flight, the velocity remains over Mach 2.5, and that therefore the choosing of 0.1 for Cd is reasonable, as at no point in the flight would it be any higher.
     
    For those planning shells other than 155mm, note that drag coefficients are constant for similar forms, regardless of scaling, but the reference area and mass scale with S^2 and S^3, respectively.
    For those considering the drag coefficient plots for more optimized projectile shapes, I suggest consulting @Sturgeon regarding drag coeffs.
  15. Metal
    Xoon got a reaction from Zyklon in Competition: Californium 2250   
    I might run with such a suspension design, seems more leak proof than a vane motor. 
     
    Honestly, I might be putting way to much time into the suspension unit, but hey, at least I know how pretty much all the hydropneumatic suspension units work in AFVs. 
  16. Metal
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    I might run with such a suspension design, seems more leak proof than a vane motor. 
     
    Honestly, I might be putting way to much time into the suspension unit, but hey, at least I know how pretty much all the hydropneumatic suspension units work in AFVs. 
  17. Tank You
    Xoon got a reaction from N-L-M in Competition: Californium 2250   
    I might run with such a suspension design, seems more leak proof than a vane motor. 
     
    Honestly, I might be putting way to much time into the suspension unit, but hey, at least I know how pretty much all the hydropneumatic suspension units work in AFVs. 
  18. Metal
    Xoon got a reaction from Sturgeon in Competition: Californium 2250   
    Been refining the suspension, currently done with the suspension arm:

     
    Next on the agenda is the suspension mount:

    Currently work is progress. 
     
     
     
     
    This is all I am going to do today, its waaay to late:

  19. Tank You
    Xoon got a reaction from Toxn in Competition: Californium 2250   
    Been refining the suspension, currently done with the suspension arm:

     
    Next on the agenda is the suspension mount:

    Currently work is progress. 
     
     
     
     
    This is all I am going to do today, its waaay to late:

  20. Tank You
    Xoon got a reaction from LoooSeR in Competition: Californium 2250   
    Been refining the suspension, currently done with the suspension arm:

     
    Next on the agenda is the suspension mount:

    Currently work is progress. 
     
     
     
     
    This is all I am going to do today, its waaay to late:

  21. Tank You
    Xoon got a reaction from N-L-M in Competition: Californium 2250   
    Been refining the suspension, currently done with the suspension arm:

     
    Next on the agenda is the suspension mount:

    Currently work is progress. 
     
     
     
     
    This is all I am going to do today, its waaay to late:

  22. Tank You
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    Been refining the suspension, currently done with the suspension arm:

     
    Next on the agenda is the suspension mount:

    Currently work is progress. 
     
     
     
     
    This is all I am going to do today, its waaay to late:

  23. Metal
    Xoon reacted to Lord_James in Competition: Californium 2250   
    More picks of the SH-1T, now with road wheels and 2 new armor cavities! 
     
     
    Weight is up to 35.86 Mg, with the suspension and wheels taking up 8.6 Mg by themselves (steel torsion bars with 850mm diameter aluminum wheels). 
     
    New Armor cavities: 
     
    6. Engine Compartment Roof: 30mm RHA + 60mm array + 30mm JPA at 7o. 992mm LoS 
    7. Crew Compartment Roof: 25mm RHA + light NERA + 36mm JPA. might reverse angle the NERA or change the material, as I'm getting disappointingly low numbers for roof protection. 
     
    I also raised the crew compartment floor, so no one can trip over the autoloader, though this reduces the head room from 1.45m to 1.26m. 
     
    near future: 
     
    A. mock up turret and carousel loader. 
    B. extend the sponsons backwards to make space for a rear idler, additional cover for the rear door, and rear aesthetics. 
    C. place ammo racks (the current front space can fit 42 charges). 
    D. armor arrays and side skirts. 
     
    later: 
     
    E. Upgrade kits 
    F. front dozer blade (a la T-72)
    G. alternate turrets/vehicles 
  24. Tank You
    Xoon got a reaction from N-L-M in Competition: Californium 2250   
    pft, who needs turrets anyways? 
     
     
    Anyways, completed my suspension unit:

     
    If anyone is interested in knowing how the suspension works, feel free to ask. 
  25. Tank You
    Xoon got a reaction from Lord_James in Competition: Californium 2250   
    pft, who needs turrets anyways? 
     
     
    Anyways, completed my suspension unit:

     
    If anyone is interested in knowing how the suspension works, feel free to ask. 
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