Microsoft Word - Assignmemt1_co
ected
MECH 3780/6480
ASSIGNMENT 1.
DUE DATE: 11:59 pm, 12 August 2022
Required:
Hand-written is not acceptable. Graphs must be produced by Excel. Explanation/analysis by Word.
Submitted version in PDF format.
Font size (including the excel graph): 12, Font name: Times New Roman, Font color black.
1. A centrifugal pump with backward-curved blades has the measured performance given in Table 1 at speed
of 1450 rpm. Tank A and B is large and open to air. The suction pipe has length L1, inner diameter D1, and friction
factor 1; the discharge pipe has length L2, inner diameter D2, and frictional factor 2. The height between two
surfaces is Z. These parameters are given in Table 2.
Questions:
a) Plot performance curves of the pump; (20 marks)
) Determine the operation point (Q, H, ) of the pump in the system, considering all the local and frictional
losses. Local loss factor at the bend (b) is given in Table 2. Density of water is =998 kg/m3, g=9.81m/s2.
(60 marks)
Table 1
Q [l/s] XXXXXXXXXX XXXXXXXXXX
H [m] XXXXXXXXXX XXXXXXXXXX
P (W XXXXXXXXXX XXXXXXXXXX44775
Table 2
Last
digit of
Student
number
System
ID Z L1(m) D1(mm) 1 b L2(m) D2(mm) 2
1 or XXXXXXXXXX XXXXXXXXXX
2 or XXXXXXXXXX XXXXXXXXXX
3 or XXXXXXXXXX XXXXXXXXXX
4 or XXXXXXXXXX XXXXXXXXXX
5 or XXXXXXXXXX XXXXXXXXXX
For example your student number is C1234567, your System ID is 2
2. An model pump delivering water at 60°C at 150 m3/h and 1450 rpm begins to cavitate when the inlet pressure
(vacuum) and velocity are 0.8 at at and 6 m/s, respectively. Find the required NPSH of the pump. (20 marks).