aero2struct_force_mapping

Maps the aerodynamic forces at the lattice to the structural nodes

The aerodynamic forces from the UVLM are always in the inertial G frame of reference and have to be transformed to the body or local B frame of reference in which the structural forces are defined.

Since the structural nodes and aerodynamic panels are coincident in a spanwise direction, the aerodynamic forces that correspond to a structural node are the summation of the M+1 forces defined at the lattice at that spanwise location.

\[\begin{split}\mathbf{f}_{struct}^B &= \sum\limits_{i=0}^{m+1}C^{BG}\mathbf{f}_{i,aero}^G \\ \mathbf{m}_{struct}^B &= \sum\limits_{i=0}^{m+1}C^{BG}(\mathbf{m}_{i,aero}^G + \tilde{\boldsymbol{\zeta}}^G\mathbf{f}_{i, aero}^G)\end{split}\]

where \(\tilde{\boldsymbol{\zeta}}^G\) is the skew-symmetric matrix of the vector between the lattice grid vertex and the structural node.

It is possible to introduce efficiency and constant terms in the mapping of forces that are user-defined. For more info see efficiency_local_aero2struct_forces().

The efficiency and constant terms are introduced by means of the array airfoil_efficiency in the aero.h5 input file. If this variable has been defined, the function used to map the forces will be efficiency_local_aero2struct_forces(). Else, the standard formulation local_aero2struct_forces() will be used.

param aero_forces:  Aerodynamic forces from the UVLM in inertial frame of reference type aero_forces:  list param struct2aero_mapping:  Structural to aerodynamic node mapping type struct2aero_mapping:  dict param zeta:Aerodynamic grid coordinates type zeta:list param pos_def:Vector of structural node displacements type pos_def:np.ndarray param psi_def:Vector of structural node rotations (CRVs) type psi_def:np.ndarray param master:Unused param conn:Connectivities matrix type conn:np.ndarray param cag:Transformation matrix between inertial and body-attached reference A type cag:np.ndarray param aero_dict:  Dictionary containing the grid’s information. type aero_dict:dict returns:structural forces in an n_node x 6 vector rtype:np.ndarray