How Do I Calculate Lift and Drag with Winglets?

[sakthivelzz]

Hi I need to know how to calculate lift characteristics like cl ,cd and so on... how can we include the winglets in it?

 

[viscousflow]

Wind tunnel... cfd... addition of winglets is a non-linear problem.

 

[sakthivelzz]

Wind tunnel... cfd... addition of winglets is a non-linear problem.

Can u explain it in more clear way please??

 

[ricky2020]

why don't you just look through Fundamental of Aerodynamics and Low speed aerodynamics books to get some sense about how to calculate lift and drag ?
Then you come up here again and ask what you need exactly. You need to specify
your flow condition like airspeed..based on that we must imposed some laws: for instance,
compressible or incompressible,potential flow is applicable or not?
Those kinda things have to consider before you get your solutions. For CFD, you must define your geometry first..then..grid..then solver like potential flow solver or Full Navier Stoke equations. I recommend you read the books I mentioned and try to get some senses firstly.
Best Regards,

 

[alphy]

Calculating lift and drag with winglets involves using the same principles and equations as calculating lift and drag without winglets, but with an additional factor for the winglets themselves.

First, let's define lift and drag. Lift is the force that acts perpendicular to the direction of motion, and is responsible for keeping the aircraft in the air. Drag is the force that acts parallel to the direction of motion, and is responsible for slowing down the aircraft.

To calculate lift and drag, we use the following equations:

Lift = ½ * p * V^2 * S * CL

Drag = ½ * p * V^2 * S * CD

Where:
p = density of the air
V = velocity of the aircraft
S = surface area of the wing
CL = coefficient of lift
CD = coefficient of drag

The coefficient of lift and coefficient of drag are determined by the shape and angle of the wing, as well as the airfoil used. These values can be found in aerodynamic tables or calculated using computational fluid dynamics (CFD) software.

Now, to include the winglets in the calculation, we need to consider their impact on the lift and drag of the wing. Winglets are small, vertical structures attached to the wingtips of an aircraft. They work by reducing the amount of vortices (swirling air) that is created at the wingtips, which in turn reduces drag and increases lift.

To account for the winglets, we can use an additional factor called the winglet efficiency factor (η). This factor is typically between 0.9 and 1, with 1 being the most efficient winglet.

The modified equations for lift and drag with winglets are:

Lift = ½ * p * V^2 * S * CL * η

Drag = ½ * p * V^2 * S * CD * η

By including the winglet efficiency factor, we can accurately calculate the lift and drag of an aircraft with winglets.

In summary, to calculate lift and drag with winglets, we use the same equations as without winglets, but with an additional factor for the winglet efficiency. This factor takes into account the impact of the winglets on the lift and drag of the wing.