Adding Kort nozzle to an existing propeller

[FAST FRED]

"I am interested in speed not more than 12 knots. So is there any modification that I can do."

Reduce the vessels weight by 50% and install 100% to 200% more power.

Going from 8K to 12K is not realistic , but reducing the fuel burn at 8K by 10% might be .

If you MUST have 12K , it will require a different boat.

FF

[TrustedShips]

Sadly, all coefficients are above 0.80.... so beyond a certain speed, probably 10 knots, the Resistance curve goes up steeply. Similar ships running at 12 knots have 850 bhp engines. so your figures are right in that respect. My idea was of an alternative modification without touching hull and engine. Can change gear ratio, shaft, propeller.