Introduction to R & P

Resistance and Propulsion of Ships Preliminary propeller design using charts

Introduction to R & P

! Example 5

Resistance and Propulsion of Ships

Bp= 10.4δ = 127

Go to chart and plot Bp-δ point. Find P/D and ηo.

Bp

δ

P/D

ηο

Introduction to R & P

! Example 5

Resistance and Propulsion of Ships

Bp= 10.4δ = 127

Find P/D and ηo.

Bp= 10.4

δ = 127

Introduction to R & P

! Example 5

Resistance and Propulsion of Ships

Bp= 10.4δ = 127

Find P/D =1.08 and ηo=0.70

Bp= 10.4

δ = 127ηο = 0.70

P/D = 1.08

Introduction to R & P

! Example 6i

Resistance and Propulsion of Ships

Bp= 29δ = 205

Find P/D =0.76 and ηo=0.585

Bp= 29

δ =205ηο = 58.5%

P/D = 0.775

Introduction to R & P

! Example 6i

Resistance and Propulsion of Ships

Bp= 29δ = 205

Line of maximum efficiency for Bp= 29 shows δ =212.

δ =212

Bp= 29

δ =205ηο = 58.5%

P/D = 0.775

Introduction to R & P

! Example 6ii

Resistance and Propulsion of Ships

€

0.1739 BP = 0.9321J

= 2.025

P/D = 0.78

ηο = 57.5 1/J=2.025

Introduction to R & P

! Example 6ii

Resistance and Propulsion of Ships

€

0.1739 BP = 0.9321J

= 2.07

P/D = 0.75

1/J=2.07