해��구조물공학 과제4- 해양구조물 외력 계산(FORCE CALCULATION)

2. Current
There are two components of current force ; and .
: drag force per unit length (N/m)
: drag Coefficient
: projected area per unit length ()
: current velocity (m/s)
But, lift force is negligible so, we only consider drag force. To calculate drag force we have to find .

3. Wind
To calculate wind force we use an equation. It defines wind force of a structure.
: wind velocity (km/h)
: projected area (m2)
: shape factor
- Beam = 1.5
- Building 면 = 1.5
- Cylindrical section = 0.5
- Platform 전체 = 1.0
: Z m에서의 wind vel. (m/s)
: 수면 위 10 m 에서의 풍속 (m/s)
: 풍속을 알고자 하는 위치 높이 (m)
:coefficient for sustained wind is 1/8
So we get wind speed at 12 meters high by following relation.
Then we finally get wind force.

4. Wave
1.1.1. Morrison Equation
: drag force
: inertia force
: seawater density = 64.2lb/ft3 = 1025 kg/m3
: inertia Coefficient .= 2.0 [DNV]
: drag Coefficient.
U : wave particle velocity