AFP - Another Fluid Pump: Airbus Challenge Winner design

Last crawled date: 1 year, 11 months ago

Please read AFP.pdf for following content
1. GENERAL INFORMATION
2. INTRODUCTION
3. SPECIFICATIONS OF PARTS AND MATERIAL
4. DETAIL DESCRIPTION
5. BLOCKED FLOW HANDLING METHOD
6. COST EFFECTIVENESS
7. INSTALLATION PROCESS
8. BILL OF MATERIAL
9. DRAWINGS

A ".STEP" model is uploaded to give the overview of assembly. All the part files are present in 'files' folder. Fasteners are not uploaded. The list of fasteners used is present in bill of material in AFP.pdf


GENERAL INFORMATION:

DIRECTION OF MOTION: Anti-Clockwise
SIZE: (l x b x h)
100 x 77x 60 mm^3 (including Box)
100 x 60 x 52 mm^3 (excluding Box)
MASS: 897.12 ± 50 grams (excluding Electronic Box)
SPACE FOR ELECTRONICS: 70 x 50 x 15 mm^3
ANGULAR VELOCITY REQUIRED FOR 7 L/MIN FLOW RATE = 1825.57 RPM
ANGULAR VELOCITY REQUIRED FOR 11 L/MIN FLOW RATE = 2868.76 RPM
OPERATING TEMPERATURE: The pump can operate between the temperature range from -20°C to 100°C provided there is no phase change of fluid. Also, it can sustain frequent thermal shift between above temperature range.
BLOCKED FLOW HANDLING METHOD: Mechanical and Electronic both
INLET OUTLET DIAMETER: 10 mm

The AFP pump is designed based on the phenomenon of Rotary Vane pump. The assembly is designed as per the regulation of CS 29 amdt 3. Following CS 29 amdt 3 general criteria, all the material used in designing the parts are accepted by European Aviation Safety Agency. Additionally, no sharp edges are exposed, all the fasteners are locked and no self-locking fasteners are used. The assembly is able to withstand up to -20 to 100 degree Celsius provided electronics and electronic box has the equivalent capability.

BLOCKAGE HANDLING
Let T be the force excreted by fluid on incline portion.
Therefore, t’ force is tending to push the rod in upward direction.
As the ROTOR is rotating with angular velocity, say W, then force exerted by BLADE is
F= mrW^2 where m, r is mass, radius
The reaction force exerted by BLADE on fluid is more than t’’.
Now, if the flow is blocked, then force exerted by Fluid is T’’, thereby T’’ >>> T
Simultaneously, the F will be reduced since W is decreased.
This leads to the upward movement of BLADES.
When the BLADES move upward, the T reduces. This let the movement of ROTOR to regain the speed. By regaining the speed, the F increases. Over all, it achieves the equilibrium position under Blocked flow circumstances.

Equilibrium condition F = T’’× sine(theta)

ADVANTAGES OF THIS METHOD
• This method of tackling the blocked flow is advantageous over electronic cut-off since this restart the flow of liquid immediately after the blockage is removed.

• Electronic cut-off switches the DC Motor off when the value of current exceeds the limited value. Though this prevents the damage, but reduces the life of motor and electronic circuit.


• This method is more reliable since it does not damage or force stops any component.

• Mechanical and electronics both constitute double blockage handling system, which is better than single one.

• Adds all the advantages of Rotary Vane Pump.

COST EFFECTIVENESS
• Vane Rotary pump is known for its complexities and huge assembly. However, here I have designed the parts like ROTOR CLAMPS, Bronze Bushes, BOX STAND which can be easily produced by simple machining operations.

• The parts that are manufactured by die (extrusion process) like MOTOR STAND, PUMP CASE, PUMP CASING CAP, MOTOR BACK SUPPORT have simple geometry, which reduces the cost of Die to minimum level.


• The thickness of wall for the casting and molding processes is kept at optimum level. This ensures that metal flow is uniform and chances of error reduce. This results in more efficient production line.

• As it was mandatory to follow the materials list used in Aviation process, the cost for preparing the structure by Aluminum proved more economical than High Quality Plastic material, which is used in aviation.


• Metal molding is more economical than plastic molding for smaller batch of product.

• Design of the ROTOR is done in the way that it does not require sophisticated tools to make. Also, the Die required for Permanent die casting is very simple, which reduces the overall cost of product.


• The use of sheet metal process to make BOX STAND adds to the cost cutting factor, and the MARKING PLATE can also be produced in bulk for future dates in a single go.

• The designing of the pump is done in segments to make sure there isn’t any complex cost draining part.