NOTE: The integrated forces computed by loadis are not the sectional forces, rather the loading forces as they are non-dimensionalized by the reference length, not the local chord. For example, the computed lift produced by loadis is cl_loadis = cl_sectional*c_local/Ref_l, where c_local is the local chord, and Ref_l is the reference length from the mixsur input file.
The FOMOCO input file is used to define the grid subsets which compose the surface of the chosen components of the configuration. The cutting planes may a series of constant x, y, or z planes. While LOADIS will perform cuts through the no-slip surfaces successfuly when the input grid file contains the entire volume grid(s), it works much faster if the input grid and solution files contain only the surfaces. Use the utilility script extractsrf and the programs SPLITMX and SPLITMQ to automatically create grid and solution files containing the surface subsets. When choosing the components for the cutting, it is best to use individual components that represent a single, complete, closed surface. If one uses a composite component that includes several bodies, such as a wing+flap+slat+body, the MINTERP sorting will not be able to discern between these different components, and the force integration will produce erroneous results.
Input variables ICUT = cutting plane (1=x, 2=y, 3=z) NREG > 0 number of regions to specify coordinate range and increment < 0 number of specified coordinates to make cuts = 0 auto determine minmax of region occupied by component If NREG>0, enter CS,CE,CINC for each region where CS = start coordinate CE = end coordinate CINC = increment else if NREG<0, enter CS for each cut where CS = coordinate of cut else if NREG=0, enter NSTA where NSTA = total number of cuts including ends endif
input_grid_filename input_solution_filename fomoco_input_parameters_filename fomoco_component_name 2 ICUT(1/2/3) 2 NREG 5.0, 18.0, 0.5 CS, CE, CINC 20.0, 23.0, 0.5 CS, CE, CINC
input_grid_filename input_solution_filename fomoco_input_parameters_filename fomoco_component_name 2 ICUT(1/2/3) -7 NREG 1.0 1.5 2.0 2.2 2.4 2.6 2.8 CS
input_grid_filename input_solution_filename fomoco_input_parameters_filename fomoco_component_name 2 ICUT(1/2/3) 0 NREG 30 NSTA
cl = -cfx*sin(alpha) + cfz*cos(alpha) cd = ( cfx*cos(alpha) + cfz*sin(alpha) )*cos(beta) - cfy*sin(beta) cs = ( cfx*cos(alpha) + cfz*sin(alpha) )*sin(beta) + cfy*cos(beta) cfx = fx/(0.5*Ref_l*M_inf*M_inf) cfy = fy/(0.5*Ref_l*M_inf*M_inf) cfz = fz/(0.5*Ref_l*M_inf*M_inf)were alpha = angle-of-attack, beta=yaw angle, Ref_l = reference length, and M_inf = freestream Mach number. These quantities are determined from the FOMOCO input file and/or the OVERFLOW solution file.
WARNING: the code currently does not read the value of beta from the OVERFLOW solution file. Non-zero values of beta must be given by the FOMOCO input file.
Output gnuplot command file: gp.com (Inside gnuplot, type "load 'gp.com'")
Authors: Stuart E. Rogers, William M. Chan, and Steven M. Nash