The dynamic mooring force on a wave energy Calculating the tensile force acting on the mooring structure from

Abstract: This thesis tries to answer the question on how to best moor a wave energy converterthat has the shape of a hose. A water wave test tank is used on a model with a scale ofapproximately 1:2.3 of that of the full size structure and the tensile force acting on themooring line is then measured with a load cell. By using Froude scaling these measuredforces are then used to predict the real force on an energy producing hose out in theocean.SWAN simulated forecasted wave data provided by the Swedish Meteorological andHydrological Institute (SMHI) is used to analyse the wave climate at five differentlocations along the west coast of Sweden and different potential test sites are listed intable 4.2. This thesis also suggests a mooring design that allowes the moored hose tomove with the waves so that dynamic load force on the mooring line can be minimized.The static load force acting on the mooring of a 48 m hose that has a diameter of 0.5 mshould range somewhere around 10-15 kN depending on wave weather and currentconditions. A dynamic load force on a hose with the same dimensions should bebetween 12-37 kN in waves that are 1.6-5 m high. Under extreme storm conditions thedynamic response to the waves could result in forces estimated at up to 5-14 times thatof the static drift force value, thus giving a dynamic force acting on the hose mentionedabove of up to 50-210 kN. The force on the hose in waves that are around 5 m highshould be at the lower end of this force span.Wave tank tests with 0.7 m waves and a period time of 2.6 s on a 36 m hose with adiameter of 220 mm resulted in a mooring tensile force of maximum 1000 N. UsingFroude scaling, the estimated dynamic force on a 83 m long hose of 0.5 m diametershould be around 12 kN in 1.6 m high waves with a period time of 3.9 s and 37 kN in 5m high waves with a period time of 3.9 s.