Reference no: EM133006047

Pumps, Compressors, Turbines and Drives:

Question 1:

In different fields industry, an efficient tip leakage management process is key to achieving high performance of the rotating machinery, as tip leakage losses may represent 1-10% of efficiency loss. For this question, write a review of existing sealing technologies (labyrinth, helical, finger, brush, leaf, etc.) in several fields of industry (steam turbines, nuclear, aircraft, hydro, etc.) and compare their potential costs and effects on leak flow rates.

Your review must contain the following items:

A) The aim of the work and key findings/arguments.

B) Evaluation of the strengths and weaknesses of different technologies

C) You are looking for a performant and cost-efficient solution for a multi-stage centrifugal pump. What technology would be the most suitable?

Question 2:

We are looking to develop a pumping solution for an air sampling device. The requirements are as follows:

• Q = 7 L/min
• dP = 100 mbar
• Rotation speed: somewhere ‘roughly' between 5 krpm and 10 krpm acceptable
• Power consumption less than 2.5 W.
• Approximate size of the pump: should fit into 50 mm x 50 mm x 50 mm box, with intake and discharge diameter tubes of 20 mm diameter

A) What are the Mach and the Reynolds numbers? What simplifications could be made here?

B) Research different pumps and select the most suitable one for the application.

C) Provide the diagrams, specifications, and detailed information including material of construction, cost, etc. for the selected pump and justify your selection with appropriate reasoning and comparisons.

D) Choose a suitable electric motor for this application

E) What would be the next steps to optimize the product design?

These references might be helpful for this task (available freely online):

• C. E. Brennen, Hydrodynamics of Pumps, 2000
• N. C. Baines, Fluid Mechanics and Thermodynamics of Turbomachinery, 2010

Question 3:

Prepare a short review of the contra-rotating fan technology. Your review must contain the following items:

A) What are the main advantages of the contra-rotating impellers? Where are they used?

B) What are the main drawbacks of this technology? Where is it hard to use them?

C) How do you optimize their efficiency? What are the main relations concerning blade angles for both impellers?

D) Calculate analytically the off-design operation blade angles.

E) Your final conclusions and recommendations supported with appropriate reference literature.