# hw 3 - CENG 101A HOMEWORK 3 D.MILLER FALL 2009 Due Thursday...

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: CENG 101A HOMEWORK # 3 D.MILLER FALL 2009 10/8/09 Due : Thursday, Read : Chapter 6 (again - especially the example Bernoulli applications) and Chapter 7 10/15/09, by 5pm at 380 EBU II, or earlier in class. Problems : 6.7 (assume P =Patm at fan exit) ; 6.27 ; 6.30 (a only ) ; 6.31 (find Q and P B only - not the time to fall 3ft); 6.32 (head loss h L is the internal energy change due to viscous dissipation – see Ex 4) Selected 6.7 : Q ~ 1 . 5 m 3 /s , Power ~ 350 watts ~ 0 . 5 hp ( Answers ( ~ means “close to”, +/- 50% ): note 1 hp = 746 watts) ; 6.27 : Δ h ~ 2" Hg ; 6.30(a ): Δh ~ 1.5 cm H 2 O ; 6.31: Q ~ 1.5 ft 3 /s , h B = (P B / ρg) ~ 20 ft of water or P B ~ 9 psi ; 6.32: Q ~ 0.05 ft 3 /s Comments on Chapter 6 : Chapter 6 is an important chapter and deals with the 1 st Law of Thermodynamics written for control volumes. The general CV equation, 6-10 , forms the basis for much of your courses in engineering thermodynamics. I would only add that we usually always select a CV such that there is no sh ear work term, δWμ /dt, which is easy since it requires viscous shear forces on a moving surface. In this fluids course all that you are expected to learn from this requires viscous shear forces on a moving surface....
View Full Document

## This note was uploaded on 10/22/2009 for the course CENG 101A taught by Professor Krashinov during the Spring '07 term at UCSD.

Ask a homework question - tutors are online