MATE1411 CAMSDM

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MATE1411 CAMSDM Major Project/Pump Design Dr
Tim Sercombe School of Mechanical Engineering
The University of Western Australia
Room 2.12 Phone [phone] email
tim.sercombe_at_uwa.edu.au
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Overview

• Part 1 Material and Process selection for a
  particular pump.

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Part 1

• Analysis and description of the expected
  application of the pump to identify the pump
  specifications and design criteria (such as flow
  rates, pressures, environments and operating
  parameters, corrosion, fatigue, life time,
  hygiene requirement, etc).
• Proper consideration for and application of
  selection strategies to the materials used in the
  construction of key components (use performance
  indices and CES where applicable).
• Processing techniques used for manufacturing
  these key components as specific and appropriate
  for the materials chosen (use CES where
  applicable).

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Part 2 Pump Design

• Two impeller designs required
• Max head
• Max efficiency.
• Need to produce
• SolidWorks 3D part for impeller A
• SolidWorks 3D part for impeller B
• SolidWorks 3D part for housing
• GibbsCAM for impeller A
• GibbsCAM for impeller B
• GibbsCAM for the impeller cavity in the housing
• GibbsCAM for the discharge hole in the housing
• SolidWorks 2D draft for impeller A
• SolidWorks 2D draft for impeller B
• SolidWorks 2D draft for housing

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Dimensional Constraints

• Housing Stock ?130 mm PVC, 35mm thick.
• Impeller Stock ?80 mm Delrin, no constraint on
  thickness.
• Check web for other dimensional tolerances and
  cutting tool sizes.

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Assessment

• SolidWorks and GibbsCAM files 30
• Report (see web for details) 60
• Oral presentation 10
• Peer assessment ?10
• Worth 45 of unit.
• Peer assessment you are to rank yourself and
  your group members on a scale of -5 to 5
• -5 very little contribution
• 5 did significantly more than their fair share
• ? 0 and individual's mark is adjusted according
  to average.

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References

• You are expect to reference extensively using the
  Harvard style (at least 10!)
• No more than 50 can be internet references.
• Library keyword search for pump design gave 17
  results.

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Important Dates

• Week 36 extra Solidworks tutorial for impeller
  design
• 17th Sept 3D files due.
• 18th and 19th Sept (in lecture time) Tutorial
  Prof Yinong Liu or myself will meet with each
  group for 10 mins to discuss problems. IF YOU ARE
  LATE YOU WILL MISS YOUR TIME!.
• Extra GibbsCam tutorial/help session
• Week 37 Friday 14 Sept, 1100am to 100pm (mid
  semester break)
• Week 38 Wednesday 19 Sept, 1100am to 100pm
• 24th Sept GibbsCam and 2D files due.

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Important Dates

• Weeks 39-41 manufacture and testing of pumps.
  Groups will sign up for a slot to see their pump
  get manufactured and then test it.
• 16th Oct Oral Presentation no more than 5 mins
  per group this will be strictly enforced and
  you will be cut off after 5 mins.
• 26th Oct Report Due.

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Major Project Tutorial
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Pump Design

• Pumping is the energy transfer from a spinning
  rotor to a fluid.
• Two components
• Impeller imparts torque from the shaft to the
  fluid
• Volute collects exiting fluid and directs it to
  the discharge pipe.

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Impeller Design

• For a given velocity maximising outlet radius and
  minimising inlet radius will give the maximum
  value of Head.
• Head Vs Flow Rate curve is characteristic of the
  pump

Max head (_at_ zero flow)
Max flow (_at_ zero head)
Head (m)
Flow Rate (l/sec)
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Pump Efficiency

• Efficiency is ratio of hydraulic power (power
  input to fluid) divided by shaft power

• Where
• Phydraulic power
• Wmmotor power (read from wattmeter)
• ?density water
• HpPump Head
• QFlow rate
• ggravity

BEP Best Efficiency Point
Head (m)
Flow Rate (l/sec)
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Hydraulic Losses

• Leakage
• Due to large clearances between impeller and
  volute.
• Recirculating flow
• Caused by flow separation, this is aggravated by
  large vane spacing and highly curved vanes.
• Friction losses
• these are increased by increasing the
  fluid-surface area - eg too many vanes.

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Hydraulic Losses

• Hydraulic shock losses
• due to a volumetric mismatch from the flow
  leaving the impeller and the flow entering the
  volute
• Entrance losses
• fluid velocity vector entering the impeller does
  not equal the entrance blade angle,
• the matching condition is known as shockless
  entry.
• A good design can have an efficiency gt50 - but
  expect 20-30 (or less!).

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Where to from here

• Tues 4/9 Lecture informal tutorial to get help
  on pump design (if you need it!).
• Wed 5/9 Lecture Industry guest lecture on
  CAD/CAM history and case studies.
• 17/18 Sept Major Project tutorial in normal
  lecture time.
• Use other time to work on you project.

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Minor Project 1 Feedback

• Generally a good job
• Couple of comments
• Machining in not automatically the cheapest
  manufacturing route.
• Always use units on your numbers
• Include coversheets with names
• Include figure captions
• Justify why a given property is important

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Minor Project 1 Feedback

• DO NOT EVER USE JARGON
• Things are not all peachy with carbon fibre
• A fork gets knocked around a bit
• Write in the third person
• Use correct names for properties
• Eg what is chemical stress?
• A less brittle material is more elastic???
• Want high hardness so that it will not fail on
  impact???
• Show your graphs!!