01resistanc_prop

# 01resistanc_prop - section 3.4 Resistance Propulsion 3.4.1...

This preview shows pages 1–3. Sign up to view the full content.

section 3.4 Resistance & Propulsion source: Woud Chapter 3 3.4.1 Hull Resistance R := c 1 v s 2 physics (3.1) P E := R v R s P E = effective_power defined (3.2) y c 0 v s physics P E c 1 v s 3 substitution (3.3) c 1 := y ( ) (3.4) y = f fouling displacement_variations ( , , sea_state , water_depth) essentially time and operations (3.5) speed dependency of c 1 .... nondimensional resistance coefficient R C T := 1 2 C T = non_dimensional_total_resistance defined (3.6) ⋅ρ⋅ A s v s 2 A s (ship surface area) not readily available, so use volume proportionality ... A s ~ Vol^2/3 P E C E := C E = specific_resistance defined (3.7) 2 3 3 ρ⋅ Vol v s since = ρ⋅ Vol Vol := ρ P E P E P E C E := C E C E := (3.8) 2 2 1 2 ρ⋅ Vol 3 v s 3 ρ⋅ 3 v s 3 ρ 3 ⋅∆ 3 v s 3 ρ C E = f Re Fr ( , , Ro , Hull_form , external_factors) dimensional analysis, physics (3.9) ρ v s Len Re := Re = reynolds_number (3.10) η v s Fr := Fr = froude_number (3.11) g Le k Ro := Ro = non_dimensional_roughness defined (3.12) Len C E = f v ( s ,∆ , fouling , Hull_form , sea_state , water_depth ) 3 P E P E R v s P E c 1 v s c 1 := R := 3 v s 9/7/2005 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
1 2 1 2 and from (3.8) P E := ρ 3 ⋅∆ 3 v s 3 C E c 1 := P E c 1 → ρ 3 ⋅∆ 3 C E (3.13) 3 v s 1 2 P E := ρ 3 ⋅∆ 3 v s 3 C E shows dependency of P E on speed and displacement e.g. if C E and v s are assumed constant ... a change in
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern