CL_fo_dragAcc

Description

• Acceleration due to atmospheric drag.

  It is parallel to the velocity vector (opposite direction), and is proportional to the velocity norm squared.

  The drag coefficient (coefd) is defined by: coefd = cd * area / mass (with cd around 2.7).

• Notes:

  - The velocity vector (vel) is the velocity relative to the atmosphere.

  - The coordinates frame can be any frame.

• See Force models for more details.

Parameters

vel:

Velocity vector (relative to the atmosphere) [m/s]. (3xN or 3x1)

rho:

Density of the atmosphere [kg/m^3]. (1xN or 1x1)

coefd:

Drag coefficient (cd*area/mass) [m^2/kg]. (1xN or 1x1)

acc:

Acceleration [m/s^2]. (3xN)

Authors

• CNES - DCT/SB

Examples

mu = CL_dataGet("mu"); eqRad = CL_dataGet("eqRad"); alt = (400:20:800)*1.e3; // altitude vel = [sqrt(mu./(eqRad+alt)); zeros(alt); zeros(alt)]; rho = CL_mod_atmUS76Density(alt); coefd = 2.7 * 10 ./ 1000; acc = CL_fo_dragAcc(vel, rho, coefd) scf(); plot(alt/1000, CL_norm(acc));