Error at line 377

[goney3]

I tried running the optimized airfoil through Xoptfoil2 at a much lower Re (100,000) and I managed to crash it... oops.

Input file:

! Easy going examaple ...
!
! Optimize min cd while keeping glide ratio of SD7003 at Reynolds 400,000 
! The optimized airfoil should have 8% thickness  
!

&optimization_options
  airfoil_file     = 'Opt5.dat'
  shape_functions  = 'hicks-henne'              ! camb-thick, bezier, hicks-henne
  show_details = .false.                        ! only minimum output on screen
/  

&particle_swarm_options
  convergence_profile = 'exhaustive'                    ! 'quick' for fast convergence (results) 
/

&operating_conditions

  dynamic_weighting      = .true.                   ! activate dynamic weighting during optimization
  allow_improved_target  = .true.                   ! results are allowed to be better than target 

  re_default       = 100000                     ! use this Reynolds number for operating points
  noppoint         = 2

  op_mode(1) = 'spec-cl'                        ! Specifiy operating point based on cl-value                        
  op_point(1) = 0.2
  optimization_type(1) = 'target-moment'
  target_value(1) = 0.0000  

  op_mode(2) = 'spec-cl'
  op_point(2) = 0.7                             ! glide ratio cl/cd at cl = 0.7
  optimization_type(2) = 'target-moment'         !   
  target_value(2) = -0.0                        ! keep the current value of SD7003
/

&geometry_targets
  ngeo_targets    = 2
  target_type(1)  = 'Camber'
  target_value(1) = 0.0200                          ! we want an airfoil family with ths camber 
  target_type(2)  = 'Thickness'
  target_value(2) = 0.18
/  

[jxjo]

Hello Keith,

... this is strange! ;-)

You didn't run 2 XO2 at the same time in the same directory? And I assume the error is not reproducible?

Could you provide the Opt5.dat airfoil?

best regards

Jochen

[goney3]

Opt5.txt Hi Jochen, I've been thinking about this error, I am wondering if it has to do with me running this on my Synology NAS drive folder? Maybe a network hiccup caused it to not be able to read/write itself while running? I haven't had it reproduceable since... :\

[jxjo]

Hello Keith,

... yes, that could be the reason! ;-) The 'write' is done some microseconds after 'read' (it is the 'run_control' file) The file handling of remote file on servers can get some timing issues ...

[jxjo]

I'll close this issue - 'hopefully' it was related to the NAS server ...