Miniature Golf Course Project - Carnival Example
Tips:
Design your Tank, Impeller, and Coil in Onshape.
Use design intent and variables to design the parts in a way where it is easy to modify key measurements/values
Measure the Volumes, Areas, and Diameters using the "Mass Properties" tool.
Input the data into the Spreadsheet.
Iterate: If you get a Red Error, change the CAD design and try again.
Algae Bio Reactor Challenge - CAD Instructions Video
Project Instructions
Overview:
Our startup is moving from the test tube phase to production. We need you to design a Bioreactor to grow our biofuel algae.
Your goal is to model a reactor in Onshape and verify it using our Digital Twin Simulator (Google Sheets). You must balance physics, biology, and economics.
Problem Statement:
Your team must design a Bioreactor Tank, Cooling Coil, and Impeller mixer to grow our biofuel algae meeting all constraints from our simulator. Your teams goal is to maximize yield, but achieve a yield of at least 100 Liters.
Requirements:
Your design must pass all 7 of these engineering checks:
Thermodynamics (The Heat Check)
Problem: Algae generate heat as they grow. If the tank gets too hot, they die.
Solution: You need a cooling coil with enough Surface Area to remove the heat.
Simulator Check: Cooling Capacity > Heat Generated
Fluid Dynamics (The Mixing Check)
Problem: If the impeller is too small, the water won't move.
Solution: Your impeller diameter must be at least 25% of the tank diameter.
Simulator Check: Impeller Diameter / Tank Diameter > 0.25
Biology (The Tip Speed Check)
Problem: If the blades spin too fast, they smash the algae cells.
Solution: Keep the RPM moderate or the diameter reasonable.
Simulator Check: Tip Speed < 2.0 m/s
Power Systems (The Motor Check)
Problem: Flat paddles (90°) and giant blades require massive energy to spin. Our motor is limited to 500 Watts.
Solution: Use Angled Blades (e.g., 45°) to slice through the water and reduce drag.
Simulator Check: Motor Power < 5 W
Aerodynamics (The Angle Check)
Problem: If the angle is too flat (0° - 20°), the blade cuts the water without pushing it.
Solution: You must have enough angle to create flow.
Simulator Check: Pumping Efficiency > 0.35
Spatial Constraints (The "Spaghetti" Check)
Problem: You cannot fill the whole tank with metal pipes; the algae need room to live.
Solution: Your cooling coil cannot take up more than 15% of the tank volume.
Simulator Check: Coil Volume / Tank Volume < 0.15
Economics & Structure (The Budget Check)
Problem: We have a budget of $500. Complex angled blades cost 2.5x more to manufacture than flat ones. Thin blades are cheap, but they snap.
Solution: Optimize your material usage. Don't make the tank bigger than necessary. Ensure blades are at least 2% as thick as they are wide.
Simulator Check: Total Cost < $500 AND Blade Thickness > 2%
Make a copy of this spreadsheet to act as your simulator.
Example prompts and tips to use Google Gemini to enhance the Engineering Design Process.
Example of a Algae Bioreactor CAD design.
Example of a Algae Bioreactor spreadsheet.