PSI - Issue 27

Muhammad Yusvika et al. / Procedia Structural Integrity 27 (2020) 109–116 Yusvika et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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the solid boundary of the propeller immersed and rotated in seawater, it allows the birth of cavitation bubbles or cavity due to differential pressure along the hydrofoil sections. It is getting the destructive and undesirable consequences of the cavitation. There are possibly damaging effects due to cavitation, such as performance loss, physical material damage, vibrations, and noise (Helal et al., 2018). Cavitation has been recognized as one of the major problems in the design and operation of a high-speed flow system. These adverse effects should be reduced entirely or possibly eliminated.

Nomenclature c

Speed of sound

Coefficient of the dimensionless wall distance

c y +

Propeller diameter

D

J Advance coefficient K Torque coefficient K T Thrust Coefficient L Characteristic length Ma Mach number n Rotational speed n pit rev

Impact in one revolution

Local pressure

P

Yield strength of the material Radius (position) of the blade section

P y

r

Radius of the propeller Reynold number Freestream velocity

R

Re

u

Reference velocity (Full scale)

u 0 v jet

Velocity of microjet

Greek symbols α ̅ λ Scale factor Dynamics viscosity density σ n Cavitation number Subscripts l Liquid M Model scale Ref Reference S Full scale v Vapor y +

The average vapor volume fraction

Dimensionless wall distance

Research on cavitation has made attention since the middle of the 18th century. Euler, Reynolds, and Parsons are the early researcher that have conducted such contribution to understanding cavitation mechanism. Cavitation research is currently advancing, not only experimental observations but also numerical simulation research. With the support of computer capabilities, allows the researcher to perform numerical study more accurate and more complexity of the case. In recent years, observation of cavitation on marine propeller has been made using several techniques to get more detailed information and to be closer to the real conditions. Full-scale observation and model scale testing has been created to develop an understanding of each behavior.