Talk:Aquarium pump
From DDL Wiki
We received your report, and you have some interesting results. Typically we expect to see your primary findings and conclusions in the executive summary, rather than needing to dig for them. Detailed comments follow:
- Please include a picture of the product
- Be sure to consider issues of cleaning and storage in addition to use. Also, the siphon appears to be used both to remove water from the tank and to clean gravel at the bottom of the tank. Are these two uses distinct?
- You might consider alternative uses for the siphon, such as emptying a waterbed or hot tub.
- Product function descriptions are relatively clear, but a figure would help. Additionally, some explanation of the physics of how a siphon functions would be helpful. The videos are interesting, but some explanation of what we are supposed to be looking at in each is in order.
- FMEA: We are surprised that hole or wear in the tube would be more likely than blockage. It seems that tube blockage is a quite likely failure mode that could be difficult to correct if the right (wrong) sided rock were to become jammed.
- DFE – your analysis is sensible, and we agree that there are likely not significant impacts associated with this product.
- For the bilge pump, it is not clear how the flapper attaches to the rest of the device. Also, was the plunger valve removed from the rest of the assembly? How is this assembled?
- The DFMA analysis is a good overview with some good ideas.
- For the fluid analysis of the bilge pump, the weight of the water lifted by the person is 1.23 lbs, but the applied force must be greater because of 1) friction forces between the piston and the sleeve, and 2) the damping force created by water moving around the seal when the piston is pressed down. Do you have intuition for which of these forces dominate and what the total applied load would be?
- For the fluid analysis of the siphon, you have some equations, but getting an estimate for this particular device is important. How are the velocity in the large and small diameter sections of the tube related? What implications does this have for cleaning? What is a reasonable number or range for fluid flow rate?
