{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ME2135_Solution_of_QUIZ_march_2009 - 03 March 2009 Metric...

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

View Full Document Right Arrow Icon
03 March 2009 Metric Number:________________ Department of Mechanical Engineering National University of Singapore ME 2135 – Fluid Mechanics II– Quiz – Dilip A Shah Time Allocated: 40 Minutes Instructions to Candidates: 1. Answer ALL questions. 2. This quiz is equivalent to 10% of the course total score. 3. Enter only your metric number on the top right corner of this page. 4. You are allowed to refer to your class lecture notes.
Background image of page 1

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

View Full Document Right Arrow Icon
Q.1 Consider two geometrically similar centrifugal pumps. One of the pumps ( pump 2 ) is four times larger than the other ( pump 1 ), i.e. D2 = 4 D1. Both pumps operate at their BEP point. (i) If both pumps pump water and use the same power , estimate the ratio of flow-rates through the two pumps, i.e. Q1 / Q2 . (ii) Compare the rotation rates of the two pumps under these conditions, i.e. N2 / N1 . (4 marks) The non dimensional variables are C Q =Q/ND 3 ; C H =gH/N 2 D 2 and C P =P/ρN 3 D 5 . Given: D 2 = 4D 1 At BEP, C H , C Q and C P will be the same for the two pumps. Also given is P 1 = P 2 .
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}