Algae Bioreactor Challenge

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:

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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%