Freeform Reflector by liaoqinmei


									Design of a
Freeform Reflector

Christine Brazill
AE 563
Final Project Part 3
May 9, 2003

  Design a double
  reflector to create a
  glare-free luminaire
  Develop lower
  reflector first using
  excel spreadsheet
  Develop upper
  reflector from lower
  and spreadsheet
Spreadsheet Setup
  Used 2.5 degree increments
  Flux of lamp and flux of desired luminaire
  Reflectance of material calculated:
    (flux of luminaire - lamp flux up) / lamp flux down
  Graphs of required cumulative reflected
  lumens and available cumulative lamp lumens
  times reflectance were created
  Lumens needed and the direction in which they
  must go were read off of the graphs
Bottom Reflector

               Angle         moves to
                       170         26.25
                       154         28.75
                       143         31.25
                    133.5          33.75
                    124.5          36.25
                       116         38.75
                       111         41.25

               Reflectance = .88
Upper Reflector
  Designed top half of upper reflector for
  rays reflected off of bottom reflector
    Reflected rays need to avoid bottom
    0 – 55 degrees

  Designed rest of upper reflector to reflect
  lamp flux
    55 – 110 degrees
Upper Reflector First Half

               Rays reflected 5
               degrees away from
               bottom reflector
               Designed from 0 –
               55 degrees from
Entire Upper Reflector
               Results of calculations for
               second half, 55 – 110°
                      Angle     Moves to
                          60       158.75
                        67.5       161.25
                          75       163.75
                        83.5       166.25
                          92       168.75
                        101        171.25
                        107        173.75
                        109         177.5
               Reflectance = .91
Full Reflector
Raytrace every 5 degrees
Full Raytrace Every 5°
 Exact calculations from spreadsheet were not
 condusive for the upper half of the top reflector
 because rays were directed back into the lower
 Spreadsheet calculations were useful for
 second half of upper reflector
 From the rough design of these reflector
 segments, a curved reflector design can be
 achieved, resulting in smoother results
 This reflector design successfully creates a
 glare-free luminaire

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