Subject: Solar chimney electrical output

From: [email-masked] (Nick Pine)
Date: 16 Sep 1996 12:48:37 -0400

10 TM=323'maximum temperature of air (K)
20 RHOM=1.2929*273/TM'air density at max temp (kg/m^3)
30 TA=302'ambient temp (K)
40 RHOA=1.2929*273/TA'air density at ambient temp (kg/m^3)
50 K=.025334'thermal conductivity of air (W/m-K)
60 G=9.8'acceleration of gravity (m/s^2)
70 CP=1012!'specific heat of air at constant pressure (J/kg-K)
80 ALPHA=.0000212'thermal diffusivity of air (m^2/s)
90 FRHO=(RHOM^8)/(RHOA^12)*(K^15)*(G^15)
100 FRHO=(FRHO/(ALPHA^5)/(CP^10)/(CP^5))^(1/11)'density factor
110 TL=313'avg temp of air under the canopy (K)
120 TS=348'surface temperature of ground under canopy (K)
130 FT=((TS-TL)/TA)^(15/11)'temperature factor
140 RR=5'rotor radius (meters)
150 RC=122'canopy radius (meters)
160 HC=195'chimney height (meters)
170 HP=.25'gap of canopy opening at the periphery (meters)
180 FG=RR^(16/11)*RC^(15/11)*HC^(15/11)/(HP^(12/11))'geometry factor
190 BIGBRACKET=FRHO*FT*FG'from equation 30 in paper
200 ETAR=16/27'rotor power coefficient (assumed to be Betz limit)
210 PR=.018*ETAR*BIGBRACKET'rotor power in watts from eqn 30
220 PRINT PR

    35.35902, ie 35 watts vs 67 kW in line 1 of Table 1 of Lodhi's paper...

Nick