CB Level III Skyward - Optimal Simulation Results (sim #0)
Engine selection
[M1419W-17]
Simulation control parameters
Resolution: 1000 samples / second.
Simulation method: Explicit Euler.Launch conditions
Altitude: 427.001 Ft.
Relative humidity: 50.000 %
Temperature: 77.000 Deg. F
Pressure: 29.920 In. Hg.
Wind speed: 15.010 MPH
Wind starts at altitude: 1.017 Ft.
Launch guide angle: 5.000 Degrees from vertical
Latitude: 31.500 DegreesSimulation Results
Maximum acceleration: Vert: 189.957 Feet/sec/sec , Horz: 16.696 Feet/sec/sec , Magnitude: 190.669 Feet/sec/sec
Maximum velocity: Vert: 827.053 ft / s , Horz: 14.073 ft / s , Magnitude: 828.532 ft / s
Maximum range from launch site: 19.572 Ft.
Maximum altitude: 8881.945 Ft.
Velocity at deployment: 33.291 ft / s
Altitude at deployment: 8877.391 Ft.
Launch guide length: 90.000 In.
Velocity at launch guide departure: 48.531 ft / s
The launch guide was cleared at : 0.363 Seconds
User specified minimum velocity for stable flight: 43.999 ft / s
Minimum velocity for stable flight reached at: 75.288 In.Time information
Time to burnout: 7.000 Sec.
Time to ejection: 24.000 Sec.
Time to apogee: 23.468 Sec.
Optimal ejection delay: 16.468 Sec.
Time to wind shear: 0.166 Sec.
Simulations 1-5 were run after the launch as part of the analysis of stresses
which occurred when the main (instead of the drogue) deployed at apogee.
Please note the deployment velocities when the launch angle varies significantly from
vertical. According to data from the altimeter, deployment of the main actually
occurred between 23 and 24 seconds after launch. This is the predicted apogee
time. That leaves wind velocity and launch angle as variables. These can cause
significant deployment velocity as shown below.
Simulation # |
Launch Rod
|
Wind Velocity
|
Deployment Velocity
|
| 0 | 5 deg | 15 starting at 1 ft agl | 33 |
| 1 | 10 deg | 15 starting at 1 ft agl | 39 |
| 2 | 15 deg | 15 starting at 1 ft agl | 98 |
| 3 | 5 deg | 40 starting at 1000 ft agl | 41 |
| 4 | 10 deg | 40 starting at 1000 ft agl | 101 |
| 5 | 15 deg | 40 starting at 1000 ft agl | 159 |
The simulation corresponding to the launch conditions showed an expected altitude of 8862 ft. The altimeters reported an averaged barometric altitude of 7565 ft and an inertial altitude of 8183 ft. This leads me to suspect horizontal velocity at deployment. Photos of the launch indicate that even with deflection of the launch rail by wind, the rocket began its flight with a deviation between 3.75 and 5 degrees from vertical.