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Wind Design Condition Studies
Methodology:
Set fin size to get lowest stability 2.5 at wind condition
Check flutter and increase fin thickness to level where flutter FOS is greater than 1.5 using increments of increasing fin thickness by one 2x2 twill on spreadsheet https://docs.google.com/spreadsheets/d/1bED5_mtsKTZOK_8UIh9m1AtHdDWtagWdZMeCRRHz9sw/edit#gid=1882516631
Enter new thickness in OR ignoring mass change and check stability still same.
get all numbers required and enter here: https://docs.google.com/spreadsheets/d/1IiWsDT2IP_I34qDOhQQSvvtqstiJyr9cIYkMXxRI6Vc/edit#gid=0
This is to help us decide what wind speed we want to design to
Cycle 2 Wind Sim 8mph
Designed fins to have min stability of 2.5 calibers at 8mph launch condition
Same as Cycle 2 sim 1 (first stab at fin size for 2.5 calibers)
Cycle 2 Wind Sim 10mph
Designed fins to have min stability of 2.5 calibers at 10mph launch condition
Cycle 2 Wind Sim 12.5mph
Designed fins to have min stability of 2.5 calibers at 12.5mph launch condition
Cycle 2 Wind Sim 15mph
Designed fins to have min stability of 2.5 calibers at 15mph launch condition
Fin Shape Testing:
Methodology: As there are too many variables to independently tweak by hand all at once and simulate the outcome of each option now that we/Joel has a basic grasp on how stable the rocket is and how different changes to the fins affect the results he will design a fin shape and then run it through a series of simulations to see if the performance of the fin is up to our desired results. If this does not result in an effective fin or Joel thinks there is performance left on the table he will repeat the process.
Characteristics to be measured:
Apogee, lowest stability prior to apogee (>5secs before apogee), lowest stability, highest stability, max velocity,
Tests to be run:
Expected flight (expected mass, length, wind, pressure, temperature)
Max and Min Mass Condition:
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Sensitivity studies on:
Other OR sim inputs
Fin shape with flutter considered
Think we should increase the fin tip chord slightly probs like 1 inch after weather thing is done.
Increasing fin thickness vs area for flutter resistance
It appears that changing fin area does not affect flutter FOS nearly as much as changing fin thickness so thickness changes will be used for weather studies.
Launch rail being shorter if want
Surface roughness improvement
Ran study on file with cycle 2 masses not quite fully done and apogee went from 29413ft to 31347ft changing from regular paint (2.36mil) to smooth paint (0.787mil). No noticeable impact on stability