Hydrauliska Strömningsmaskiner
Hydrauliska Strömningsmaskiner
Hydrauliska Strömningsmaskiner
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3.3.4 Avsvarvning av pumphjulet..................................................................................... 37<br />
3.4 Kavitation ....................................................................................................................... 37<br />
3.4.1 Kavitationens inverkan på pumpens prestanda........................................................ 37<br />
3.4.2 Kavitationskriterier.................................................................................................. 38<br />
3.5 Utförande av pumpar ...................................................................................................... 39<br />
3.5.1 Hjul- och skovelformer............................................................................................ 40<br />
3.5.2 Axeltätningar ........................................................................................................... 41<br />
3.5.3 Pumphusets utförande.............................................................................................. 44<br />
3.5.4 Speciella pumpar av centrifugaltyp ......................................................................... 48<br />
3.5.5 Centrifugalpumpar med högre specifikt varvtal ...................................................... 53<br />
3.5.6 Diagonalpumpar ...................................................................................................... 53<br />
3.5.7 Axialpumpar (propellerpumpar).............................................................................. 54<br />
3.5.8 Material i pumpar .................................................................................................... 55<br />
3.6 Provning av pumpar........................................................................................................ 56<br />
4. FLÄKTAR............................................................................................................................ 57<br />
4.1 Fläktdiagram................................................................................................................... 57<br />
4.2 Dimensionslösa tal.......................................................................................................... 60<br />
4.3 Omräkning av fläktdiagramdata för olika densiteter ...................................................... 61<br />
4.4 Fläktar som ljudkälla ...................................................................................................... 62<br />
4.5 Fläktars utförande ........................................................................................................... 63<br />
4.5.1 Konstruktionstyper .................................................................................................. 63<br />
4.5.2 Exempel på utförande av radialfläkt........................................................................ 64<br />
4.5.3 Översikt av fläktars användningsområden............................................................... 65<br />
5. VATTENTURBINER ......................................................................................................... 66<br />
5.1 Fallhöjd........................................................................................................................... 66<br />
5.2 Peltonturbiner ................................................................................................................. 67<br />
5.3 Francisturbiner................................................................................................................ 69<br />
5.4 Axialturbiner................................................................................................................... 72<br />
5.5 Jämförelser mellan olika turbintyper .............................................................................. 74<br />
6. STRÖMNINGEN I SKOVELHJUL..................................................................................... 76<br />
6.1 Inledning......................................................................................................................... 76<br />
6.2 Skovlarnas och skovelgittrets uppgift............................................................................. 76<br />
6.3 Idealt strömningsförlopp................................................................................................. 76<br />
6.3.1 Radialhjul................................................................................................................. 76<br />
6.3.2 Axialhjul .................................................................................................................. 77<br />
6.4 Orsaker till skillnaden mellan verkligt och idealt strömningsförlopp ............................ 79<br />
6.4.1 Slip........................................................................................................................... 80<br />
6.4.2 Gränsskiktsströmning .............................................................................................. 81<br />
6.4.3 Avlösning................................................................................................................. 83<br />
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