Illumination Calculation Method of New Street Teeb
Koj tuaj yeem xaiv ob peb lub ntsiab lus sawv cev ntawm txoj kev thiab suav lawv qhov illuminance. Cov txheej txheem yog me ntsis nyuaj, tab sis qhov tseeb ntawm kev xam yog siab. Hauv kev xyaum, feem ntau tsuas yog cov ntsiab lus nrog qhov siab tshaj plaws thiab qis tshaj qhov pom tau raug suav. Xam cov illuminance ntawm ob lub ntsiab lus AB raws li qhia hauv daim duab 18-11. Tus nqi illuminance ntawm point A yog proportional rau lub teeb siv lub teeb ntawm lub teeb qhov chaw nyob rau hauv PA kev taw qhia, thiab inversely proportional rau lub square ntawm qhov deb PA, uas yog
E＝I(Q, φ)cosQ/(PA)2
Xam qhov illuminance ntawm cov ntsiab lus A thiab B
Vim PA·cosQ=H, PA=H───cosQ
So PA2＝H2─── cosQ(18-2)
Ntawd yog, E＝I(Q, φ)/H2·cos2Q
Nyob rau hauv cov mis, I (Q, φ) ─ Lub luminous siv ntawm lub teeb qhov chaw nyob rau hauv lub PA kev taw qhia yuav tau txais raws li lub teeb tis nkhaus;
H - qhov siab ntawm lub teeb ci / m;
Q─ Lub kaum sab xis ntawm txoj kab ntsug ntawm lub teeb ci mus rau hauv av thiab PA. tus
Nyob rau hauv cov piv txwv saum toj no, yog hais tias lub illuminance ntawm lub teeb nyob rau hauv av point B yog xam, nrhiav pom ∠BPO nyob rau hauv txoj cai daim duab peb sab BOP,
Tom qab ntawd: tg(90 degree －∠BPO)－∠BPO)－H/B＝7/13＝0.54 tuaj yeem xam ∠BPO＝62 degree, cos∠BPO＝cos62 degree ＝0.47 thiab tom qab ntawd nrhiav cov ntsiab lus B raws li lub teeb faib nkhaus ntawm lub teeb DDY400 Lub teeb siv kuv (lossis kos tawm ntawm iso-kev siv nkhaus daim duab). Tshawb tawm ntawm daim duab uas lub teeb siv thaum ∠BPO=62 degree yog 66cd. Vim hais tias lub teeb faib nkhaus no yog ua raws li cov luminous flux ntawm lub teeb ci li 1000lm, thiab cov luminous flux ntawm lub teeb ci GGY400 peb xaiv yog 21500lm, yog li 66cd yuav tsum tau muab faib ua 21.5 npaug. Yog li ntawd, qhov illuminance ntawm point B yog
E＝I(Q, φ)/H2·cos3Q
＝I/H2·∠BPO
=66×21.5/72×0.473
=6.40(lx)
