Sheet1Parshall Flume Calculations - S.I. units2. Flow Rate for Submerged Flow (1' to 50' Throat Width)Equations for Calculation of Flow Rate under Submerged Conditions:Enter measured Ha and Hb for correct Throat Width, W. The spreadsheet will calculate1. For 0.3 m < W < 2.44 msubmergence ratio, Hb/Ha; Q calculated for free flow, Qfree; correction forsubmergence, Qcorr; and the flow rate for submerged flow, Qsubm.Qsubm = Qfree - QcorrThroatSubmerg.Qcorr = (3.738/106) M (Ha/0.3048)2.123 e9.284SWidthRatio, SQfreeQcorrQsubmW, m.Ha*, mHb*, m(Hb/Ha)m3/sm3/sm3/sW, mM0.3050.30480.243840.80.11330.00628363280.1070.30510.4570.30480.243840.80.16990.00879708590.1610.4571.40.6100.30480.243840.80.22660.0113105390.2150.611.80.9140.30480.243840.80.33980.01508071860.3250.9142.41.2190.30480.243840.80.45310.01947926160.4341.2193.11.5240.30480.243840.80.56630.02324944120.5431.5243.71.8290.30480.243840.80.67910.02701962090.6521.8294.32.1340.30480.243840.80.79300.03078980050.7622.1344.92.4380.30480.243840.80.90620.03393161690.8722.4385.43.0480.30480.243840.81.1150.00654129211.1093.6580.30480.243840.81.3240.0078504091.316For 0.03 m < W < 2.44 m , S < 0.7 is needed for free flow.4.5720.30480.243840.81.6380.00981193821.6286.0960.30480.243840.82.1590.01308258422.1462. For 3 m < W < 15 m7.6200.30480.243840.82.6810.01635323032.6649.1440.30480.243840.83.2040.01962387633.184Qsubm = Qfree + Qcorr12.190.30480.243840.84.2480.02616087624.22215.240.30480.243840.85.2910.03270646055.258Qcorr = (W/3.048)(0.30483) (3.364 + 20.19 S2 ln S )2* For the locations in the flume to measure Ha and Hb, see the following article:For 3 m < W < 15 m , S < 0.8 is needed for free flow.Open Channel Flow Measurement 2: The Parshall Flume

Open Channel Flow Measurement 2: The Parshall Flume

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