CL_fo_dragAcc

Description

• Perturbing acceleration (relative to an inertial frame) 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));