How make a waterbird (pumpabike)


I am an Engineering science student doing my fifth year at Technology University in Vietnam. Part of our studies involves a final year project, and I have selected one on building a water craft similar in principle to the waterbird. Part of this project will primarily involve modelling this craft, how it works, simulation operation, structure analysis. Ultimately we will build a full size craft and test the design. However, some problems in structure and operating priciples which i don't understand, such as:
- Properties spring?
- Why they choose NACA 63-412?
- time of a cycle action (jump down--> jump up) and amplitude ( only consider rear wing)?
- properties aluminium used?

Please answer some question?
Capacity of English is bad. So, I don't clearly describle my desires. I hope you will sympathize.

Very thanks! I hope you will answer in short time!

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perhaps it is too late for you, but I saw waterbird this morning for the first time and I was very impressed for its performance.

I think amplitude must be sychronized with average frecuency of a man 70 kg weight then solving the bouyancy for this frecuency in a differential equation, you will have diameter of vertical cylinder and rear large wing, considering also the drag of the large wing to the upward and downward velocity.

part of the force is derived to front small wing that must be sunk on the water, enough to change the angle of the rear wing to produce a forward motion when sunk, and again change the angle of the rear wing in the opposite angle when bouyancy return the movement upwards; producing again a forward movement.

Very interesting artefact.

caitlinsdad7 years ago
quangtruc106 (author)  caitlinsdad7 years ago
I read this site. But i don't find the informations which i need. Please help me!
That's because these are all patented products and sold by manufacturers for profit. That said, you need your engineering skills to deduce some of the parameters. Build a model to test and subject it to analysis. What doesn't work you modify or change. Observe carefully and record.

1. Fiberglass spring -is it a pole, solid rod, fiber bundle?  You can look up materials properties or test.  What is the force of a man jumping up and down to get it to move?  What is the sound of one hand clapping?
2. Looks like some airfoil design specification.  Was it the best to give the machine lift or drag in the water?
3. Watch the videos and time the operation.  Put a ruler up to the computer display.
4. What kind of aluminum tubing, maybe even square stock or some other shape will hold up to the forces exerted?

It's your design, giving a straight answer will not help you.  Good luck.

quangtruc106 (author)  caitlinsdad7 years ago
Very thanks! I will research continuously. I think i need you help again. So, u can give your email, please? My email is quangtruc106@gmail.com.
Thanks again! I hope i will receive your answers in short time!