"
With more focus on space flight applications " (as per
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1301658#msg1301658)
the metric chosen by the NASA's "Anomalous" report was the thrust force per power input.EDIT: Dimensions for Shawyer's and Brady et.al.'s cavities updated as per latest estimates on 05/20/15Here is a comparison of reported measurements for EM Drives and for the latest report by Fearn, Zachar, Woodward & Wanser.
Notice that the force per power input reported by Fearn, Zachar, Woodward & Wanser is several orders of magnitude lower than the "EM drives". Actually it is barely (3.5 times higher) more than the force per power input of a photon rocket:
reported measurement ForcePerPowerInput (milliNewtons/kW)
(* Cannae Superconducting *) 761.9 to 952.4
(* Shawyer Demo *) 80 to 243
(* Shawyer Experimental *) 18.82
(* Brady c TE mode *) 21.31
(* Brady a TM mode*) 5.396
(* Brady b TM mode*) 3.000
(*Fearn, Zachar, Woodward & Wanser*) 0.01176
lengths in meter
rfFrequency in 1/second (microwave frequency during test)
power in watts
force in milliNewtons
force per PowerInput in milliNewtons/kW
c= 299705000 m/s (speed of light in air)
c= 299792458 m/s (speed of light in vacuum) (for Cannae Superconducting)
(the difference between c in air compared to c in vacuum is negligible)
Note: SmallDiameter for Shawyer's EM Drives obtained from his reported ShawyerDesignFactor .
Force/PowerInput of a Photon Rocket = 1 / c
(* Cannae Superconducting *)
rfFrequency = 1.047*10^9;
cavityLength = 0.01+0.004+0.006+0.01 = 0.03;
bigDiameter =(22.86-2*(0.00430)) = 0.220;
smallDiameter = bigDiameter-2*0.01=0.200;
power = 10.5
Q = 1.1*(10^7)
measured force = 8 to 10
measured ForcePerPowerInput = 761.9 to 952.4
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket = 228,400 to 285,500
(* Shawyer Experimental *)
rfFrequency=2.45*10^9;
cavityLength=0.156;(estimated from photographs)
bigDiameter=0.16; (given by Shawyer)
smallDiameter=0.1025; (obtained from the Design Factor, bigDiameter and frequency provided by Shawyer)
Design Factor = 0.497;
power = 850;
Q = 5900 ;
measured force = 16
measured ForcePerPowerInput = 18.82
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket =5,640
(* Shawyer Demo *)
rfFrequency=2.45*10^9;
cavityLength=0.345;(estimated from photographs)
bigDiameter=0.28;(given by Shawyer)
smallDiameter= 0.09613; (from the Design Factor, bigDiameter and frequency provided by Shawyer)
Design Factor = 0.844;
power = 421 to 1200;
Q = 45000;
(measured force = 102.30 milliNewtons only reported for 421 watts, 243 milliNewtons/kW )
measured ForcePerPowerInput = 80 to 243
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket =23,980 to 72,830
All Brady cases have the following dimensions:
cavityLength=0.2286; (provided by Paul March)
bigDiameter=0.2794; (provided by Paul March)
smallDiameter=0.15875; (provided by Paul March)
(* Brady a TM mode*)
rfFrequency=1.9326*10^9;
power = 16.9
Q = 7320
measured force = 0.0912
measured ForcePerPowerInput = 5.396
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket =1,617.2
(* Brady b TM mode*)
rfFrequency=1.9367*10^9;
power = 16.7
Q = 18100
measured force = 0.0501
measured ForcePerPowerInput = 3.000
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket =899.12
(* Brady c TE mode *)
rfFrequency = 1.8804*10^9;
power = 2.6
Q = 22000
measured force = 0.05541
measured ForcePerPowerInput = 21.31
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket =6,386.7
(* Fearn, Zachar, Woodward & Wanser*)
rfFrequency = 39,300;
power = 170
measured force = 0.002
measured ForcePerPowerInput = 0.01176
Force/PowerInput of a Photon Rocket =0.003337
measured ForcePerPowerInput to the one of a photon rocket = 3.526