Discussion
An aeroplane has a Dutch roll with \( \zeta = 0.08 \) and \( \omega_n = 1.5 \ \mathrm{rad/s} \). Against requirements of \( \zeta \geq 0.08 \) and \( \zeta\omega_n \geq 0.15 \ \mathrm{rad/s} \), the aeroplane
Answer: D
The damping ratio is exactly at its limit, but the product is \( 0.08 \times 1.5 = 0.12 \ \mathrm{rad/s} \), short of the 0.15 required, so the aeroplane meets one criterion and fails the other. This is exactly why specifications state both: a low frequency mode can satisfy a damping ratio while still taking too long in absolute time to decay, and it is the product that fixes the decay rate. Raising the damping ratio to 0.10 would clear it.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development