JN-Engineering Wind Tunnel Project
Authors: Jacob Poore (Jacob-Poore) & Noah Lim (Lim-Noah)
Repository: github.com/JN-Engineering/wind-tunnel
Last Updated: October 4, 2025
1. PROJECT OVERVIEW
1.1 Purpose
This document compares two build configurations for our closed-circuit wind tunnel project:
- Config A (Budget Build): Educational/demo facility with manual instrumentation
- Config B (Research Build): Automated data acquisition with improved material quality and enhanced structure
We are weighing whether to build a low-cost version—making the educational investment more easily replicable for future students, or to invest upfront in higher-quality instrumentation. This analysis compares actual component costs and capabilities to guide our decision.
2. CONFIGURATION A: BUDGET BUILD
2.1 Complete Bill of Materials
| Line | Source | Description | Notes | Qty | Unit Cost ($) | Total Cost ($) | Category |
|---|---|---|---|---|---|---|---|
| 1 | Amazon | PLA Filament, 1.75 mm | 1 kg spool | 5 | 28.00 | 140.00 | Materials & Structure |
| 2 | Home Depot | Acrylic Sheets | 24″ × 36″ | 3 | 32.09 | 96.27 | Materials & Structure |
| 3 | Home Depot | MDF Board | 16″ × 20″ | 10 | 9.00 | 90.00 | Materials & Structure |
| 4 | Home Depot | Plywood | 4′ × 4′ | 4 | 22.00 | 88.00 | Materials & Structure |
| 5 | Fabricated | Modular Wall Panels | cut from wood/acrylic | 36 | 0.00 | 0.00 | Materials & Structure |
| 6 | Fabricated | Contraction Nozzle | MDF/3D printed | 1 | 0.00 | 0.00 | Materials & Structure |
| 7 | Fabricated | Observation Panels | Acrylic windows | 3 | 0.00 | 0.00 | Materials & Structure |
| 8 | Unknown | Silicone Rubber Sheet | High-temp gasket | 1 | 10.00 | 10.00 | Materials & Structure |
| 9 | Unknown | Fasteners M3–M8 | Assorted | 1 | 10.00 | 10.00 | Materials & Structure |
| 10 | Unknown | Load Cell 0–5 kg | Analog output | 3 | 15.00 | 45.00 | Instrument & Data |
| 11 | Fabricated | Model Hardware Mount | 1 | 0.00 | 0.00 | Instrument & Data | |
| 12 | Unknown | ADC Module | e.g., HX711 | 1 | 4.00 | 4.00 | Instrument & Data |
| 13 | Unknown | Pitot Tube | Velocity measurement | 1 | 5.00 | 5.00 | Instrument & Data |
| 14 | Unknown | Differential Pressure Sensor | Analog | 1 | 15.00 | 15.00 | Instrument & Data |
| 15 | Fabricated | Flow Straightener | Honeycomb/fabricated | 1 | 0.00 | 0.00 | Air Flow |
| 16 | Fabricated | Turbulence Screens | Fine mesh | 2 | 0.00 | 0.00 | Air Flow |
| 17 | Salvaged | Axial Fan | 1 | 0.00 | 0.00 | Air Flow | |
| 18 | Unknown | Micro Servo | Generic RC servo | 1 | 15.00 | 15.00 | Control & Electrical |
| 19 | Unknown | Arduino Uno R3 | Controller | 1 | 25.00 | 25.00 | Control & Electrical |
| 20 | Unknown | 12 V Power Supply | Wall adapter | 1 | 10.00 | 10.00 | Control & Electrical |
| 21 | Unknown | Adhesives & Consumables | Epoxy, drill bits | 1 | 6.00 | 6.00 | Contingency & Misc |
| 22 | N/A | Project Contingency Reserve | Shipping/misc | 1 | 20.00 | 20.00 | Contingency & Misc |
Configuration A Total: $579.27
2.2 Equipment List
| Equipment | Description | Notes | Unit Cost ($) | Total Cost ($) |
|---|---|---|---|---|
| Bamboo H2D | 3D Printer | Used for fabricating PLA structural parts and small fixtures | 0 | 0 |
| EPILOG HELIX | Laser Cutter | Used for cutting acrylic panels and MDF sheets | 0 | 0 |
| Fog Machine | Airflow Visualization Device | Using propylene glycol fluid; Alternatively scavenged heating elements | 40 | 40 |
| Safety | Eye Protection, Fire extinguisher | 0 | 0 | |
| Technical Documentation Package | CAD, Reports, Repo | Astro PDM, Github, Cloudflare | 0 | 0 |
| Precision Tools | Calipers, Micrometers, Gauges | 0 | 0 | |
| PIM Shooter 300A | Injection Molder | 0 | 0 | |
| Formech 450DT | Thermoformer | 0 | 0 |
2.3 Cost Breakdown by Category
| Category | Line Items | Subtotal ($) | Percentage (%) |
|---|---|---|---|
| Air Flow | 3 | 0.00 | 0.0 |
| Contingency & Misc | 2 | 26.00 | 4.5 |
| Control & Electrical | 3 | 50.00 | 8.6 |
| Instrument & Data | 5 | 69.00 | 11.9 |
| Materials & Structure | 9 | 434.27 | 75.0 |
3. CONFIGURATION B: ENHANCED BUDGET
3.1 Complete Bill of Materials
| Line | Part Number | Description | Notes | Qty | Unit Cost ($) | Total Cost ($) | Category |
|---|---|---|---|---|---|---|---|
| 1 | N/A | PETG Filament, 1.75 mm | 1 kg spool | 8 | 24 | 192 | Materials & Structure |
| 2 | N/A | Acrylic Sheet (2-pack) | 24″×36″ | 4 | 28 | 112 | Materials & Structure |
| 3 | N/A | MDF Board | 16″×20″ | 10 | 15 | 150 | Materials & Structure |
| 4 | N/A | Marine Plywood | 4′×8′ panel | 1 | 85 | 85 | Materials & Structure |
| 5 | N/A | Contraction/Diffuser | CNC machined | 1 | 120 | 120 | Materials & Structure |
| 6 | Fabricated | Polycarbonate Panels | UV-resistant | 4 | 35 | 140 | Materials & Structure |
| 7 | Fabricated | Silicone Gaskets | High-temp cut | 1 | 35 | 35 | Materials & Structure |
| 8 | N/A | Precision Fastener Kit | Traceable hardware | 1 | 62 | 62 | Materials & Structure |
| 9 | Unknown | Load Cell 0–5 kg (precision) | High accuracy | 3 | 12 | 36 | Instrument & Data |
| 10 | Fabricated | Precision Sting Mount | CNC/lathe | 1 | 45 | 45 | Instrument & Data |
| 11 | Unknown | 24-bit ADC | High-res converter | 2 | 8 | 16 | Instrument & Data |
| 12 | Unknown | Pitot-Static Probe | Lab-grade | 1 | 35 | 35 | Instrument & Data |
| 13 | Unknown | Digital Pressure Transducer | USB output | 2 | 25 | 50 | Instrument & Data |
| 14 | Unknown | USB Data Logger | For ADC | 1 | 18 | 18 | Instrument & Data |
| 15 | Unknown | Hot-wire Anemometer | 0.05–50 m/s | 1 | 55 | 55 | Instrument & Data |
| 16 | Unknown | Calibration Weight Set | 100 g–1 kg | 1 | 35 | 35 | Instrument & Data |
| 17 | Fabricated | Honeycomb Flow Straightener | Grid flow | 1 | 45 | 45 | Air Flow |
| 18 | Unknown | Turbulence Screens (40 mesh) | 4 units | 4 | 15 | 60 | Air Flow |
| 19 | Unknown | Centrifugal Blower | 120 V, 3000 RPM | 1 | 120 | 120 | Air Flow |
| 20 | Unknown | ESP32 Dev Board | Wi-Fi/BT | 1 | 55 | 55 | Control & Electrical |
| 21 | Unknown | Digital Servo 20 kg·cm | Metal gear | 2 | 25 | 50 | Control & Electrical |
| 22 | Unknown | Regulated 24 V Power Supply | 10 A, EMI filtered | 1 | 85 | 85 | Control & Electrical |
| 23 | Unknown | 7″ TFT Display | Touchscreen HDMI | 1 | 45 | 45 | Control & Electrical |
| 24 | Unknown | Professional Smoke Generator | 1000 W DMX | 1 | 65 | 65 | Contingency & Misc |
| 25 | Unknown | LED Light Bar | 5000 K dimmable | 1 | 30 | 30 | Contingency & Misc |
| 26 | Fabricated | Vibration Isolation Mounts | Rubber-steel | 1 | 40 | 40 | Contingency & Misc |
| 27 | Unknown | Project Contingency Reserve | 5% materials/shipping | 1 | 100 | 100 | Contingency & Misc |
Configuration B Total: $1,881.00
3.2 Equipment List
| Equipment | Description | Notes | Unit Cost ($) | Total Cost ($) |
|---|---|---|---|---|
| Bamboo H2D | 3D Printer | Used for fabricating PLA structural parts and small fixtures | 0 | 0 |
| EPILOG HELIX | Laser Cutter | Used for cutting acrylic panels and MDF sheets | 0 | 0 |
| Professional Smoke Generator | Airflow Visualization Device | 65 | 65 | |
| Safety | Eye Protection, Fire Extinguisher | 0 | 0 | |
| Technical Documentation Package | CAD, Reports, Repo | Astro PDM, Github, Cloudflare | 0 | 0 |
| Precision Tools | Calipers, Micrometers, Gauges | Astro PDM, Github, Cloudflare | 0 | 0 |
| PIM Shooter 300A | Injection Molder | 0 | 0 | |
| Formech 450DT | Thermoformer | 0 | 0 | |
| CNC Machine | Precision Machining | 0 | 0 |
3.3 Cost Breakdown by Category
| Category | Line Items | Subtotal ($) | Percentage (%) |
|---|---|---|---|
| Air Flow | 3 | 225 | 11.96 |
| Contingency & Misc | 4 | 235 | 12.49 |
| Control & Electrical | 4 | 235 | 12.49 |
| Instrument & Data | 8 | 290 | 15.42 |
| Materials & Structure | 8 | 896 | 47.63 |
4. HEAD-TO-HEAD COMPARISON
4.1 Cost Summary
| Metric | Configuration A | Configuration B | Delta (B - A) |
|---|---|---|---|
| Total Material Cost | $579.27 | $1,881 | + $1,301.73 |
| Number of Line Items | 22 | 27 | +5 |
| Average Cost per Item | $26.33045 | $69.66667 | + $43.33621 |
| Highest Single Item | PLA Filament, 1.75 mm $140 | PETG Filament, 1.75 mm $192 | + $52 |
| Salvaged Components | 7 items ($0) | 0 items | -7 items |
| Contingency Reserve | $20 | $100 | + $80 |
4.2 Category Spending Comparison
| Category | Config A ($) | Config B ($) | Delta ($) |
|---|---|---|---|
| Air Flow | 0.00 | 225 | 225.00 |
| Contingency & Misc | 26.00 | 235 | 209.00 |
| Control & Electrical | 50.00 | 235 | 185.00 |
| Instrument & Data | 69.00 | 290 | 221.00 |
| Materials & Structure | 434.27 | 896 | 461.73 |
4.3 Key Differences
Configuration A (Budget Build)
- Relies on salvaged components
- Manual data recording required
- Basic analog sensors
- Single-speed fan operation
- Simple Arduino Uno controller
- Propylene glycol fog for visualization
Configuration B
- All purchased components
- Automated data logging with USB interface
- Digital sensors with documented accuracy
- Variable speed blower with VFD capability
- Enhanced structural integrity with higher-durability materials
5. OUR TAKE
5.1 Reality Check
Config A is doable on a student budget due to our access to salvaged parts and free equipment. We estimate the cost to replicate for a third-party would be 200-300 dollars higher solely for materials.
Config B is more expensive but better suited for research. It would also allow for more long-term use of the Wind Tunnel.
5.2 Plan
Phase 1 Priorities:
- Build the tunnel structure (Config A)
- Get basic flow visualization working
- Validate velocity measurement with pitot tube
Phase 2 Upgrades (if budget allows):
- Swap to centrifugal blower (+ $120) → better flow control
- Add 24-bit ADC + data logger (+ $34) → automated logging
- Upgrade pressure sensors (+ $85) → better accuracy
- Add flow conditioning (+ $105) → improved flow quality
6. APPENDICES
6.1 Abbreviations
- ADC = Analog-to-Digital Converter
- BOM = Bill of Materials
- CFD = Computational Fluid Dynamics
- CNC = Computer Numerical Control
- EMI = Electromagnetic Interference
- FS = Full Scale
- I2C = Inter-Integrated Circuit (serial protocol)
- MDF = Medium-Density Fiberboard
- NIST = National Institute of Standards and Technology
- PETG = Polyethylene Terephthalate Glycol
- PLA = Polylactic Acid (3D printer filament)
- PWM = Pulse Width Modulation
- TIR = Total Indicator Runout
- USB = Universal Serial Bus
- VFD = Variable Frequency Drive
6.2 Version History
| Version | Date | Author | Changes |
|---|---|---|---|
| 0.1 | 2025-9-26 | Jacob & Noah | Initial Setup of BOM |
| 0.2 | 2025-9-27 | Jacob & Noah | Budget A and Budget B |
| 0.3 | 2025-10-02 | Jacob Poore | Initial Price Sourcing |
| 0.4 | 2025-10-04 | Jacob Poore | Added visualization graphs |
| 1.0 | 2025-10-04 | Jacob Poore | First Release |
License:
| Component | License |
|---|---|
| Hardware & Software | MIT |
| BOM & Documentation | CC BY 4.0 |