Hello dear fluent user,

I am trying to calculate a lift coefficient on a 3D hydrofoil at different angles with some constant velocity say 5 m/sec. My problem is that when i performed a simulation on simple 3d hydrofoil with its moving part at 4 deg. angle of attack it gives value of CL = 0.156

When i attached the 3d Hydrofoil with the aftsection of the hull and again performed the simulation with the same operating conditions just an addition of hull appendage interaction it gives the value of CL = 0.351

For both the cases i used the same reference value i.e. the chord length, span and reference area of moving plane. Please help me in this matter i think i might be doing something wrong in calculating the lift co-efficent. Can anyone share with me the literature on hull appendage interaction regarding lift calculations. Hoping for an early response. Thanks in advance.

you are asking the same question for months

the matter is, no one wants to give their hard to gain related experiences for free rightfully.

no pain no gain so keep studying or fail...

First, mak sure that you have fully converged solutions by monitoring the lift on the hydrofoil.

Then, I would take a look at the inflow to the hydrofoil when it's in freestream and when it in the hull's wake to see if there is a significant change in the "effective" angle of attack of your hydrofoil relative to the inflow. If the hydrofoil is immersed in the stern wake, chance is that the inflow would be substantially different from that for a freestream, which will change the lift on the hydrofoil with flap.