How Is Static Thrust Calculated for Quad Rotor UAVs?

[rubai]

I want to make a quad rotor UAV. i studied a lot but i did not find how static thrust is being calculated. In physics forum i have found an equation which is given below but i can not understand what is 'frac' and 'rho'.
Equation is:
T=\frac{c_T}{c_p}\frac{P}{nD}

Where:
P = power (ft-lb/s or kWW)
T = Thrust (lb or kN)
D = Prop Diameter (ft or m)
n = rotation speed (rev/s)
c_P = Power coefficient
c_T = Thrust coefficient

And:

c_P=\frac{P}{\rho n^3 D^5}

c_T = \frac{T}{\rho n^2 D^4}

 

[SteamKing]

\frac is badly formed latex. If you provide a link to the earlier post, that may help someone interpret the formulas. rho is probably the density of the fluid in which the rotor or propeller is acting.

 

[NatSusan]

Hello there! I am not an expert in quad rotor UAVs, but I can try to help you understand the equation you found.

First, let's break down the equation into smaller parts. The equation is used to calculate the static thrust of a quad rotor UAV. Static thrust is the force produced by the propellers when the UAV is not moving.

T=\frac{c_T}{c_p}\frac{P}{nD}

T is the symbol for thrust and is measured in pounds or kilonewtons. This is the force that the propellers produce.

c_T is the thrust coefficient, which is a dimensionless value that represents the efficiency of the propellers in converting power into thrust. It is dependent on the design and shape of the propellers.

c_p is the power coefficient, which is also a dimensionless value that represents the efficiency of the propellers in converting power into thrust. It is dependent on the design and shape of the propellers.

P is the power of the propellers, measured in foot-pounds per second (ft-lb/s) or kilowatts (kW). This is the energy that is used to rotate the propellers.

n is the rotation speed of the propellers, measured in revolutions per second (rev/s). This value is important because it affects the efficiency of the propellers.

D is the propeller diameter, measured in feet or meters. This value is important because it affects the amount of air that the propellers can move.

Now, let's look at the equations for c_P and c_T:

c_P=\frac{P}{\rho n^3 D^5}

c_T = \frac{T}{\rho n^2 D^4}

In these equations, \rho (rho) represents the air density, measured in slugs per cubic foot or kilograms per cubic meter. This value is important because it affects the amount of air that the propellers can push.

So, to summarize, the equation for static thrust takes into account the power, rotation speed, propeller diameter, and air density, as well as the efficiency of the propellers (c_P and c_T). The values of c_P and c_T can be calculated based on the design and shape of the propellers. I hope this helps!