Question

Problem #2 A duct 2m by Ime in size carrying conditioned air runs in a straight line for Umrom the supply an. It divides into two parts each of 80 m long and 2 m m Section as shown in Fig. 20.6. T 80 m Fan 50 m 80m — Fig. 20.6 Insulated air ducts. If the quantiry of air discharged at C is 1600 m/min, calculate the quantity discharged at D and the static pressure at the fan outler A. Calculate the duct friction loss in Nm taking the alue of friction factor as 0.005.

Answer 1

Cven dala 5am, ,-4on, s Bom fo. 0054 A 2x1 A arb N2 3 160nmn fer v APply mais cohservehon 2 So B 8. C disclanye at D. 1,8uommn13-3s 3 N3- A3 2J m2 Ar A, A 2 Ve lauty hae R 2 = 04vl p veloit paeune in 3C. (P), 0.6(,)2 0.4x(13-3) Jo- ab 2(at) due to fiction ()s 21 2( 2t1) Hydaaullic dia. 0-005x80x106-6- 128 m press Loss in Bc Total paese at , e= (P4)3+ (K 128+ 1o 6. 234.6 N2 ) paemre toss in 3D, (42- i2.C 00s0,, 3.2(., N/ from D , (R,1o6. GN P2 o.4 C) V2 13-33ms Quantity ot ai dischayed at D, aAr 21333- 2666 m/s14 ms Dn Dn (3 32cro = 26 66ts 2. Q,-021 03 160+ 1Coo32co mmn velocity haasuse ih duet Ab, (),o. C 0x(264)2-427 N paenuse loss in Ab, P4 = fu.CR), = 0.005x50 x427: 32o N/m2 Dn 1/3 Total boersur ad APA fe+(Pf) 234.6132054,6m Ps PA-(P) Stahe toemac ad fan, (ol A). S54.6427 fs 127.6 Nhw Ars