STRUCTURES IN MIKE 21. Flow over sluice gates A-1

Transcription

1 A-1 STRUCTURES IN MIKE 1 Fl ver luice gate Fr a give gemetry f the luice gate ad k ater level uptream ad dtream f the tructure, the fl rate, ca be determied thrugh the equati f eergy ad mmetum - ee B Pedere, ref. /17/. Thi apprach ill be ued i the fllig. Water depth ad ater level are pecified accrdig t a k referece level, ee figure B.1. Mrever b ad b dete the idth f the chael uptream ad dtream f the luice gate Referece level η y η η y y Figure B.1 Sketch f defiiti f ymbl Fr fl up t a give magitude the fl rate ill be determied by the large headl hich ccur right dtream f the luice gate. I thee ituati bth the equati f eergy ad mmetum huld be emplyed, ad the fl rate deped bth uptream ad dtream ater level. Cider t cr-ecti: Oe uptream f the luice gate ad e at the pit dtream f the luice gate, here the fl btai miimal idth. The ater level i thi cr-ecti i deted η. Becaue f the hrt ditace ad due t the fl t expadig i the cidered dmai, fricti ad headl ca be eglected. The equati f eergy fr the t cr-ecti i the η = η g b ( y ) g b ( y ) η η Frm the pit ith ater level η t the pit dtream f the luice gate here the fl agai i uifrmly ditributed ver the cr-ecti a large l f eergy ccur due t the expai f the fl. Thu the equati f mmetum i ued fr calculati i thi dmai: 1 1 ' ρ ρgb ( η y ) = ' ρ ρgb b b ( η y )

2 A- ' ' I the abve equati ad dete the fl ditributi cefficiet uptream ad dtream f the tructure, repectively. A gd apprximati f thee cefficiet i 1.0. With k value f uptream ad dtream ater level, η ad η, the equati f eergy ad mmetum ctitute a ytem f t equati ith t uk variable, amely fl rate ad ater level η. (The latter i t f ur iteret i the actual ituati.) A bth equati are -liear they mut be lved by iterati. Thi ca eaily be de after me imple maipulati. Fr trg fl critical fl ca ccur due t the high fl velcity thrugh the luice gate. I thi ituati the uptream ater level ad the gemetry f the luice gate determie the fl rate ad the equati f eergy yield: η y g b 3 = 3 = gb Thi equati explit that the velcity height i the pit here critical fl ccur, exactly equal half f the preure head. Uually the velcity height uptream ca be eglected (lat term the left-had ide); the the equati ca be lved explicitly fr the critical fl rate. If the velcity height uptream i t mitted the equati mut be lved by iterati. The ay f determiig hich methd that huld be ued i a give ituati i the fllig: Calculate the fl rate by bth methd uig the give ater level. The methd that yield the mallet fl rate i the crrect methd fr the actual ituati. Figure B. h the fl rate veru uptream ater level, calculated by the abve methd. Fr the calculati the fllig value ere ued 1 3 η y y y b b b 0 m -5 m -5 m -.7 m 100 m 0.3 m 100 m

3 A Fl rate (m3/) Figure B. Fl rate veru uptream ater level Fr the cidered iterval f uptream ater level, critical fl thrugh the luice gate de t ccur, thu ly the methd decribed at firt ha bee ued.

4 Bprit=true Opti fr additial prit i lg file Iclude_Structure=true Tur the tructure pti Ntruct=1 Number f tructure t be read Struct_area(1)=3 The tructure i placed i area 3 Struct_type(1)=1 Idetifier fr tructure type: 1. brad-creted eir Struct_jtart(1)=39 Struct_jtp(1)=39 Struct_ktart(1)=4 Struct_ktp(1)=30 Struct_rietati(1)=1 Struct_headl_i(1)=1.0 Struct_headl_ut(1)=.0 Struct_table_le(1)=5 Struct_table_urf(1,1)= -.7 Struct_table_urf(1,)= 0.4 Struct_table_urf(1,3)= 0.94 Struct_table_urf(1,4)=.73 Struct_table_urf(1,5)= 10.0 Struct_table_area(1,1)= 0.0 Struct_table_area(1,)= 51.0 Struct_table_area(1,3)= 65.0 Struct_table_area(1,4)=179.0 Struct_table_area(1,5)= Delh=0.05 Itermax=100 Struct_ctrl(1)=true Struct_ctrl_cle(1,000000)=1 Struct_ctrl_cle(1,000004)=0 Struct_ctrl_cle(1,000008)=1 Struct_ctrl_cle(1,01960)=0 Struct_ctrl_cle(1,0590)=0 Mdel crdiate fr the tructure Mut be grid aliged at preet Idetifier fr tructure rietati: 1: parallel t y-axi. parallel t x-axi L cefficiet fr i- ad utfl Number f etrie i table Table value f ater level (urf) ad cr-ecti area (area) Iterati limit (i metre) Max iterati if true: it ca be pecified that the luice gate are cled i a part f the imulati perid The luice gate are cled (1) frm timetep 0 t 4, pe (0) frm 5 t 8 ad cled agai frm timetep 9 t 1960 i the imulati.

5 [OPTION_PARAMETERS] bprit = true Iclude_Structure = true truct = 1 truct_area_001 = truct_type_001 = 1 truct_jtart_001 = 98 truct_jtp_001 = 98 truct_ktart_001 = 54 truct_ktp_001 = 55 truct_rietati_001 = 1 truct_headl_i_001 = 1 truct_headl_ut_001 = truct_table_le_001 = 5 truct_table_urf_001_001 = -. truct_table_urf_001_00 = 0.4 truct_table_urf_001_003 = 0.94 truct_table_urf_001_004 =.73 truct_table_urf_001_005 = 10 truct_table_area_001_001 = 0 truct_table_area_001_00 = 51 truct_table_area_001_003 = 65 truct_table_area_001_004 = 179 truct_table_area_001_005 = 1117 delh = 0.05 itermax = 100.truct_ctrl_001 = true truct_ctrl_cle_001_ = 1 truct_ctrl_cle_001_ = 0 truct_ctrl_cle_001_ = 1 truct_ctrl_cle_001_ = 0 truct_ctrl_cle_001_00100 = 1 EdSect // OPTION_PARAMETERS