Simrad SU90 - Problems with Flow Noise; Noise;Speed Test Results

Finaltestsandmeasurements
Problemswithownoise
Incaseofveryhighshipnoiselevels,theRCGfunctionwillautomaticallyregulatethe
receivergaindown.Thislowergainwillthencauseareductioninthereceivingrange.
Tondoutifthishighnoiseleveliscausedbyownoisefromthevessel’shullorbythe
engine/propeller,performthefollowingtest.
Bycomparingthesethreeresultingplotsitshouldbepossibletosortoutifthemainnoise
iscausedbyownoiseorengine/propellernoise.Ifthemainnoiseiscausedbyow
noise,theship’shullshouldbethoroughlyinspectedduringnextdocking.Ifthenoiseis
causedbytheenginepropeller,ensurethatthepropellerisnotchippedorcorroded.
1Enterthenoiselevelfor0degreesbearingfromtheNoisemeasurementstableinto
thecolumnforStablespeedintheNoisevericationtable.
2From0knots,givefullenginethrust,andmakearead-outofthenoiselevelfor
accelerationwhenthevesselreacheseachofthelistedspeeds.Entertheresults
intothetable.
3Fromfullspeed,reducetheenginethrustforminimumspeed,andrecordsimilar
resultsforretardation.
4MakeadashedlineplotoftheaccelerationnoiseintotheNoise/speedplot,and
adottedlinefortheretardationnoise.
Noise/speedtestresults
Thetablesandplotcreatedforthetestresultsareprovidedbelow.
Noisemeasurementsresults
Table7Noisemeasurements
Bearing
Speed—120°—60°0°+60°+120°+180°
0knots
2knots
4knots
6knots
8knots
10knots
12knots
14knots
16knots
381293/A
207