P09454: Design and Testing of Centrifugal Pump Components

Set Final Specifications

Final Engineering Specification

The table below presents the metrics, or engineering specifications, and short comments on the team assessment of the attainability of the engineering goals.

Engineering Specifications
Spec. No. Specification Priority Units Minimum Ideal Maximum Status Comments
1 System Efficiency 1 % 60 85 100 Unlikely Calculated system efficiency <<60%
2 Unique Impeller Designs 1 Piece 3 3 Likely Approximately 8 Designs
3 Unique Diffuser Designs 1 Piece 2 2 Likely 2 Designs
4 Unique Volute Designs 1 Piece 1 2 Likely 1 Designed
5 Create System Pressure Differential 2 PSI 5 10 15 Likely Calculated >5psi
6 Rotational Speed 3 rpm 1750 1750 1750 Likely Already Achieved
7 System Top Height 2 in 42 45.15 48 Likely Design is 46.75in.
8 System Center Line Height 2 in 40 42 44 Likely Design is 41.75in.
9 Withstand Operational Stress 1 FOS 2 4 Likely Analysis suggests
10 Pump Contains System Pressure 1 FOS 2 5 Likely Calculation >2
11 Ability to Control Motor Speed 2 rpm +/- 1 +/- 1 +/- 1 Likely Already Achieved
12 Ability to Control System Flow 2 in +/- 0.1 +/- 0.1 +/- 0.1 Likely Already Achieved
13 Measure Flow w/ GUI 2 Binary Yes Yes Yes Likely Already Achieved
14 Measure Pressure Differential w/ GUI 2 Binary Yes Yes Yes Likely Already Achieved
15 Measure Motor Speed w/ GUI 2 Binary Yes Yes Yes Risk No Connection
16 Measure Motor Current w/ GUI 2 Binary Yes Yes Yes Risk No Connection
17 Control System Flow w/ GUI 2 Binary Yes Yes Yes Likely Already Achieved
18 Control Motor Speed w/ GUI 3 Binary Yes Yes Yes Risk No Connection
19 LOS for PIV 1 Transmissivity 75% 85% 100% Likely Approximately 92% before machining
20 Tool Clearance 1 in 0.25 0.45 2.0 Likely 2in in design
21 Impeller Change-Out Time 1 min 0 5 10 Likely Previous team performed in <10. The new design has measures to further reduce the time.
22 Spillage 1 ml <40% <20% < 5% Likely Analysis
23 Withstand drop from 42in. 1 Binary Yes Yes Yes Risk Current Impeller is ok
24 Assembly w/o Power Tool Requirement 3 lbf 0 2 7 Likely Required no excessive force to assemble/disassemble

Meeting Specifications Summary

The project is highly likely to meet 19/24 target specifications as outlined in the Table except Spec 1, Spec 15, Spec 16 , Spec 18 and Spec 23. Here, Spec 1 is a high priority specification; Spec 15 & Spec 16 are moderate priority and Spec 18 is low priority.

The team is highly unlikely to meet the requirements of Spec 1. The engineering analyses of the current designs show that the team is not in a position to achieve a level of efficiency between 60% and 100%. Furthermore, the team does not foresee any design changes in the volute, impellers or diffuser which will meet the target specification. If possible, the team will consult with the customer to revise the target specification based on the empirical results of the fabricated components.

The team is concerned about meeting Spec 15, Spec 16 and Spec 18 which deal with the interaction of the Graphic User Interface and the Motor Control Module. Therefore, measuring and controlling the motor parameters from the GUI is not currently possible. The team has added the required materials (DB9 to RJ45 adapter cable, Serial communication port replicator card) to the BOM and will begin repairing the GUI/Motor Control connection as materials become available. The team has planned to assign adequate time and resources to achieving these specifications and is moderately confident of success.

Spec 23 relates to the durability of the fabricated parts in order to withstand a drop from a height of 42 in. The current impeller survives a fall of such a height and thereby the team is confident that they will be able to meet the specification. However, the new impeller designs are more complex and intricate and thereby are a higher risk of damage. Therefore, the team is cautious about this specification.

For information on how the target specifications relate to the customer needs, please review the House of Quality documentation below:

House Of Quality