A compar-ison was made between friction factors and head losses found with design estimate, calculated with the IBA-method and from measured head loss, for the headrace tunnels of three hydroelectric power plants (HEP).
Samanburður var gerður á milli núningsstuðla og falltapa reiknaða með hönnunarútreikningum, með IBA-aðferðinni og fundna út frá mældu falltapi, fyrir þrjár vatnsaflsvirkjanir.