erj145-yasim.xml

<?xml version="1.0" encoding="ISO-8859-1"?>


<!-- Buck notes:
ERJ-145XR (or LR with a few mods)

base operating weight	27758 lbs
max zero fuel weight	40785 lbs
max takeoff weight	53131 lbs
max landing weight	44092 lbs
max payload		13027 lbs

Vmo	0.80M/320 kts (XR)
Vmo	0.78M/320 kts (LR)
Vle	250 KIAS
Vlo	200 KIAS
Va	200 KIAS
Vfe	250 KIAS	9 degrees
Vfe	200 KIAS	18 degrees
Vfe	200 KIAS	22 degrees
Vfe	160 KIAS	45 degrees (XR)
Vfe	145 KIAS	45 degrees (LR)

max fuel imbalance	800 lbs
max positive load	2.5G with no flaps
			2.0G with flaps
max negative load	-1G with no flaps
			0G with flaps

The CG range of a -145 is fairly narrow, about 20% to 27% MAC.

This is not meant to be an accurate simulation of the XR, but it should be sufficient for
most VA pilots. Climb rates are reasonable, stall is about right, top end cruise
is about right. Range needs to be checked, as does cross-wind handling, but they're likely
not terrible. If you change this FDM, be sure that you KNOW WHAT YOU ARE DOING
otherwise you could turn a reasonable flying model into an unreasonable flying model.

Gary Neely "Buckaroo", May 2015

-->


<airplane mass="27758" version="YASIM_VERSION_CURRENT">


<!-- Buck notes:
Typical approach for this thing:
begin downwind at 180 KIAS, gear up, flaps up
mid downwind at 160 KIAS, gear up, flaps 9 degrees
end downwind at 140 KIAS, gear down, flaps 22 degrees
base leg at 140 KIAS, flaps 22 or 45 degrees
final at Vref + gust + 1/2 wind

Using the idea that V2 is at least 120% Vs, I'm guessing that stall could be anywhere from 90 to 115
depending on weight and OAT.

Using the given weights, the solution is using a total weight of 37983 lbs + fuel.
-->

<approach speed="140" aoa="4" fuel="0.3">
  <control-setting axis="/controls/engines/engine[0]/throttle" value="0.2"/>
  <control-setting axis="/controls/engines/engine[1]/throttle" value="0.2"/>
  <control-setting axis="/controls/flight/flaps" value="1.0"/>
  <control-setting axis="/controls/gear/gear-down" value="1"/>
  <solve-weight idx="0" weight="1800"/>
  <solve-weight idx="1" weight="6000"/>
  <solve-weight idx="2" weight="1800"/>
  <solve-weight idx="3" weight="625"/>
</approach>

<cruise speed="470" alt="37000" fuel="0.6">
  <control-setting axis="/controls/engines/engine[0]/throttle" value="0.95"/>
  <control-setting axis="/controls/engines/engine[1]/throttle" value="0.95"/>
  <control-setting axis="/controls/flight/flaps" value="0"/>
  <control-setting axis="/controls/gear/gear-down" value="0"/>
  <solve-weight idx="0" weight="1800"/>
  <solve-weight idx="1" weight="6000"/>
  <solve-weight idx="2" weight="1800"/>
  <solve-weight idx="3" weight="625"/>
</cruise>


<!-- Buck notes:
Variable weights to represent passengers and baggage. Being a fairly small airliner, the ERJ-145
has a fairly narrow balance range. It is not uncommon for passengers in the first three or last
three rows to be asked to move in order to re-distribute weight.
These positions are simple estimates.
-->
<weight x="7.5"    y="0" z="-0.75" mass-prop="/sim/weight[0]/weight-lb"/> <!-- First three rows -->
<weight x="-0.483" y="0" z="-0.75" mass-prop="/sim/weight[1]/weight-lb"/> <!-- middle rows -->
<weight x="-3.8"   y="0" z="-0.75" mass-prop="/sim/weight[2]/weight-lb"/> <!-- Last three rows -->
<weight x="-7.5"   y="0" z="-0.75" mass-prop="/sim/weight[3]/weight-lb"/> <!-- baggage -->


<cockpit x="11" y="0.4" z="-0.1"/>


<fuselage ax="14.92427" ay=" 0.00000" az="-1.48220" bx=" 12.37025" by=" 0.00000" bz="-1.06748" width="1.654" taper="0.2" midpoint="1.0"/>
<fuselage ax="12.37025" ay=" 0.00000" az="-1.06748" bx=" 10.87561" by=" 0.00000" bz="-0.69382" width="2.355" taper="0.7" midpoint="1.0"/>
<fuselage ax="10.87561" ay=" 0.00000" az="-0.69382" bx=" -6.43974" by=" 0.00000" bz="-0.69382" width="2.355" taper="1.0" midpoint="1.0"/>
<fuselage ax="-6.43974" ay=" 0.00000" az="-0.69382" bx=" -9.42322" by=" 0.00000" bz="-0.64353" width="2.355" taper="0.8" midpoint="0.0"/>
<fuselage ax="-9.42322" ay=" 0.00000" az="-0.64353" bx="-12.90208" by=" 0.00000" bz="-0.21357" width="1.900" taper="0.2" midpoint="0.0"/>

<!-- Buck notes:
I'm not bothering with making fuselage elements from engine nacelles. By design these have little drag impact.
-->

<!-- Left engine -->
<!--
<fuselage ax="-5.48830" ay=" 2.10926" az="-0.09991" bx=" -9.79638" by=" 2.10926" bz="-0.09991" width="1.383" taper="0.8" midpoint="0.2"/>
-->

<!-- Right engine -->
<!--
<fuselage ax="-5.48830" ay="-2.10926" az="-0.09991" bx=" -9.79638" by="-2.10926" bz="-0.09991" width="1.383" taper="0.8" midpoint="0.2"/>
-->


<!-- Buck notes:
Supercritical airfoils for modern airliners vary with the span, are proprietary, and
are beyond YASim's scope, so I'm not even going to bother researching this one.
Numbers here are guesses that should work OK for an airliner of this type.

Flap drag and lift values are guesses, but reasonable.

The -145 does not have slats. It has a small fixed leading edge droop and vortilons.
The model also has slats; these should be removed (or at least disable the animations).

Incidence is a guess, but reasonable. It gives the aircraft some ground visibility on approach,
and keeps the fuselage reasonably level at cruise, a requirement for most airliners.

I shift the wings forward 0.2m to compensate for YASim lift and moment force application.
original wing locations: x="-0.30450" x="-0.83468"

Aileron effects should not be too great. The ERJ-145 is known to be a bit heavy in roll response,
particularly at low speeds.
-->

<!-- Inboard segment -->
<mstab x="-0.10450" y="1.127" z="-1.70136"
       chord="4.2"
       length="2.550"
       taper="0.70"
       sweep="12"
       dihedral="3.4"
       incidence="2.5"
       camber="0.01">
       <stall aoa="13" width="7" peak="1.5"/>
       <flap0 start="0" end="1" lift="1.35" drag="2.4"/>
       <spoiler start="0" end="1" lift="0.5" drag="1.5"/>
       <control-input axis="/controls/flight/spoilers" control="SPOILER"/>
       <control-input axis="/controls/flight/flaps" control="FLAP0"/>
       <control-output control="SPOILER" prop="/surface-positions/speedbrake-pos-norm"/>  
       <control-output control="FLAP0" prop="/surface-positions/flaps-pos-norm"/>
       <control-speed control="FLAP0" transition-time="7"/>
       <control-speed control="SPOILER" transition-time="1"/>
</mstab>


<!-- Outboard segment -->
<wing x="-0.63468" y="3.61689" z="-1.55343"
      chord="2.942"
      length="6.384"
      taper="0.42"
      sweep="19.382"
      dihedral="3.4"
      incidence="2.5"
      twist= "-2"
      camber="0.01">
      <stall aoa="13" width="7" peak="1.5"/>
      <flap0 start="0.0" end="0.5" lift="1.35" drag="2.4"/>
      <flap1 start="0.5" end="1.0" lift="1.16" drag="1.15"/>
      <control-input axis="/controls/flight/flaps" control="FLAP0"/>
      <control-input axis="/controls/flight/aileron" control="FLAP1" split="true"/>
      <control-input axis="/controls/flight/aileron-trim" control="FLAP1" split="true"/>
      <control-output control="FLAP0" prop="/surface-positions/flap-pos-norm"/>
      <control-output control="FLAP1" side="left" prop="/surface-positions/left-aileron-pos-norm"/>
      <control-output control="FLAP1" side="right" prop="/surface-positions/right-aileron-pos-norm"/>
      <control-speed control="FLAP0" transition-time="7"/>
</wing>


<!-- Buck notes:
The elevator should be fairly strong, since the -145 remains senstive to pitch even at lower speeds.
If there's any under-camber, it's not very signficant.
-->
<hstab x="-13.06474" y="0" z="3.11266"
       chord="1.937" 
       length="3.698" 
       taper="0.626"
       sweep="14.166"
       camber="0">
       <stall aoa="17" width="4" peak="1.5"/>
       <flap0 start="0" end="1" lift="1.53" drag="1.4"/>
       <control-input axis="/controls/flight/elevator" control="FLAP0"/>
       <control-input axis="/controls/flight/elevator-trim" control="FLAP0"/>
       <control-output control="FLAP0" prop="/surface-positions/elevator-pos-norm"/>
</hstab>


<!-- Buck notes:
Not sure if the rudder effectiveness is reasonable. It may be too strong, but I haven't conducted
any cross-wind tests. It should be able to handle up to 30 knots under good conditions.
-->

<vstab x="-10.94804" y="0" z="-0.01304" 
       chord="3.752" 
       length="4" 
       taper="0.45"
       sweep="34">
       <stall aoa="16" width="4" peak="1.5"/>
       <flap0 start="0" end="1" lift="1.3" drag="1.3"/>
       <control-input axis="/controls/flight/rudder" control="FLAP0" invert="true"/>
       <control-input axis="/controls/flight/rudder-trim" control="FLAP0" invert="true"/>
       <control-output control="FLAP0" prop="/surface-positions/rudder-pos-norm" />
</vstab>


<!-- Buck notes:
The LR model uses either the Rolls-Royce AE 3007-A1 2ith 7800 lb thrust or
the Rolls-Royce AE 3007-A1P with 8300 lb thrust.
The XR model uses theRolls-Royce AE 3007-A1E with 8700 lb thrust.
I don't know what ambient temperatures are used for these thrust ratings, so they
may not match with YASim, which uses the standard atmosphere temp of 15C.
Dry weight for these models is about 1,585 lb.
SFC unknown but may be about 0.39. It's a very efficient engine.
Max N1: 100%
Max N2 for A1 and A1P: 102.4%
Max N2 for A1E: 105%
EPR? Does the engine instrumentation even use this?

These are of course turbofan engines and YASim doesn't well simulate high-bypass engines.

An action point of x=-8.78 is too far back. Turbofan engines get most of their thrust from the
bypass air powered by the forward fan, so most thrust is delivered to that fan's thrust bearing.
Let's just use the center of mass for the action point.
-->
<jet x="-7.3" y="2.11"  z="-0.1"
     mass="1585"
     thrust="8700"
     tsfc="0.39"
     epr="5.66">
     <actionpt x="-7.3" y="2.11"  z="-0.1"/>
     <control-input axis="/controls/engines/engine[0]/throttle" control="THROTTLE"/>
     <control-input axis="/controls/engines/engine[0]/mixture" control="MIXTURE"/>
     <control-input axis="/controls/engines/engine[0]/reverser" control="REVERSE_THRUST"/>
     <control-output control="REVERSE_THRUST" prop="/surface-positions/reverser-norm[0]"/>
     <control-speed control="REVERSE_THRUST" transition-time="1.5"/>
</jet>

<jet x="-7.3" y="-2.11" z="-0.1"
     mass="1585"
     thrust="8700"
     tsfc="0.39"
     epr="5.66">
     <actionpt x="-7.3" y="-2.11"  z="-0.1"/>
     <control-input axis="/controls/engines/engine[1]/throttle" control="THROTTLE"/>
     <control-input axis="/controls/engines/engine[1]/mixture" control="MIXTURE"/>
     <control-input axis="/controls/engines/engine[1]/reverser" control="REVERSE_THRUST"/>
     <control-output control="REVERSE_THRUST" prop="/surface-positions/reverser-norm[1]"/>
     <control-speed control="REVERSE_THRUST" transition-time="1.5"/>
</jet>


<!-- Buck notes:
Transition time of gear is currently unknown, 7 secs is a guess.
Actual compressions are unknown, using the modeler's guess.

Note that the model has the main gear deployed more than half a meter too far back.
Even without good diagrams, it's evident from photos that the tires are a full tire diameter
forward of the wing trailing edge. Position should be about 0.55 forward, more or less.
old: x=-1.662, new: x=-1.112
The model and animations should be changed to correct this.
-->

<!-- nose -->
<gear x="12.652"  y="0" z="-3.06"
      compression="0.2" 
      spring="1" 
      damp="1" >
      <control-input axis="/controls/flight/rudder" control="STEER" square="true"/>
      <control-input axis="/controls/gear/gear-down" control="EXTEND"/>
      <control-output control="EXTEND" prop="/gear/gear[0]/position-norm"/>
      <control-speed control="EXTEND" transition-time="7"/>
</gear>

<gear x="-1.112" y="2.054" z="-3.35" 
      compression="0.25" 
      spring="0.85" 
      damp="1" >
      <control-input axis="/controls/gear/brake-left" control="BRAKE"/>
      <control-input axis="/controls/gear/brake-parking" control="BRAKE"/>
      <control-input axis="/controls/gear/gear-down" control="EXTEND"/>
      <control-output control="EXTEND" prop="/gear/gear[1]/position-norm"/>
      <control-speed control="EXTEND" transition-time="7"/>
</gear>

<gear x="-1.112" y="-2.054" z="-3.35" 
      compression="0.25" 
      spring="0.85" 
      damp="1" >
      <control-input axis="/controls/gear/brake-right" control="BRAKE"/>
      <control-input axis="/controls/gear/brake-parking" control="BRAKE"/>
      <control-input axis="/controls/gear/gear-down" control="EXTEND"/>
      <control-output control="EXTEND" prop="/gear/gear[2]/position-norm"/>
      <control-speed control="EXTEND" transition-time="7"/>
</gear>


<!-- Buck notes:
The LR/XR version has two fuel tanks, one in each wing, of 5717 lbs capacity. The tanks
occupy the center of the wing between the spars from root to a fair way toward the tip.
These tanks have three or four sub-sections divided by one-way baffles fitted with check valves,
such that fuel drains inward toward the root where the fuel collection sumps are located.
The left tank normally feeds the left engine, the right tank feeds the right.
Cross-feeding is available, but fuel cannot be transferred between tanks.

The XR version has an additional ventral tank with a capacity of 1863 lbs. This tank is probably
located in the belly just forward of the main gear retracted position. Note that there is a
ventral skid at that location designed to help protect the tank in the event of a gear-up landing.
The skid is one way to easily identify the XR version. The 3D model lacks this feature.

To simulate the wing tanks, it would be best to create three tanks per wing to represent the
baffled regions. The outermost tank would drain first, then the center, then the inboard last.
In this way, the tanks drain appropriately and handling improves as fuel is used.
This will need a custom Nasal fuel handling script, which the model should have anyway.

Tanks in order of:
left wing (5717 lbs, 39 lbs unusable)
right wing (5717 lbs, 39 lbs unusable)
center (1863 lbs, 21 lbs unusable)
-->
<tank x="-0.483" y="4"  z="-1.5" jet="true" capacity="5717"/>
<tank x="-0.483" y="-4" z="-1.5" jet="true" capacity="5717"/>
<tank x="-0.483" y="0.00"  z="-1.75" jet="true" capacity="1863"/>


<!-- Buck notes:
CG range of about 20% to 27% MAC.
27% MAC: x=-0.540
25% MAC: x=-0.483
-->
<ballast x="10" y="0" z="-0.75" mass="4200"/>

</airplane>