Aerospace Engineering + Physics
Make a model wind tunnel and test shapes
Build a small wind tunnel from a fan and straws and compare the drag of different shapes.
- DifficultyIntermediate
- Estimated time1–2 weeks
- Budget₹500–₹1,000
- ClassClass 9 to college
- Team2–3 people
- You needHousehold materials
Prerequisites: Idea of force and air resistance
Original · by TechnifyedEngineering DesignInvestigationResearch orientedWell documentedTwo subjects
Overview
A fan pulls air through a box. A honeycomb of drinking straws straightens the flow, and a test object mounted on a lever pressing on a scale gives a drag reading.
Why build this?
You get real aerodynamic data for the price of a fan, and can test your own car or wing shapes.
What you will learn
- How flow straighteners make smooth air
- How drag depends on shape
- How to measure a small force with a lever
- How to compare shapes fairly
Skills you will use
Safety
- Power tools and moving parts can injure. Use them only with training and supervision, wear eye protection and keep hair and sleeves clear.
- This project uses a blade or sharp tool. Cut away from your body on a cutting mat, and ask an adult to help younger students.
Materials and tools
- Cardboard or acrylic box (about 60 cm long)
- Table fan or exhaust fan
- 200 drinking straws
- Digital kitchen scale
- Wire and card for the mount
- Clay for shapes
Tools and software
Step-by-step roadmap
Start
You will finish with: a working tunnel and a drag table for four shapes.
- 1
Prerequisites
Know this first: idea of force and air resistance. Then collect the 6 items in the materials list.
- 2
Learn
- How flow straighteners make smooth air
- How drag depends on shape
- How to measure a small force with a lever
- How to compare shapes fairly
- 3
Plan
Sketch the design, list every part with its price and decide how you will know it works.
- 4
Build
- Build a rectangular tunnel with a clear window.
- Pack straws at the inlet as a flow straightener and mount the fan at the outlet.
- Make a pivoted arm that holds the object in the flow and presses on the scale outside.
- Shape a sphere, a cube, a teardrop and a flat plate with the same frontal area.
- Record the scale reading for each with the fan on and off.
- Rank the shapes by drag.
- 5
Test
Reversing the teardrop should clearly increase its drag.
- 6
Document
Photograph each build stage, keep the circuit or drawing, and note what failed and how you fixed it. Report structure
- 7
Present
Demonstrate it working first, then explain how it works and what you would improve. Presentation structure · Viva questions
- 8
Publish
Share a short video, the parts list and the drawing or code so someone else can build it.
Expected outcome
A working tunnel and a drag table for four shapes.
Other versions of this project
Beginner version
Compare just a flat plate and a teardrop.
Advanced version
Add smoke or thread tufts to see the flow, and measure lift on a wing at several angles.
Research version
Measure drag at three fan speeds and test whether it grows with speed squared.
Make this project better
- BasicCompare just a flat plate and a teardrop.
- This projectMake a model wind tunnel and test shapes
- AdvancedAdd smoke or thread tufts to see the flow, and measure lift on a wing at several angles.
- ResearchMeasure drag at three fan speeds and test whether it grows with speed squared.
Ways to do this project
Text marked "You write this" is a prompt for your own work; everything else is specific to this project.
- Problem
- How does the shape of an object change its air drag?
- Hypothesis
- If a shape tapers gently at the back, then its drag will be lower than a blunt shape of the same frontal area.
- Variables
- Independent: object shape. Dependent: drag force reading. Controlled: frontal area, fan speed, position in the tunnel
Materials and procedure are in Materials and the Roadmap.
Observation table
| Shape | Reading off (g) | Reading on (g) | Drag (g) |
|---|---|---|---|
- Graph
- Bar chart of drag for each shape
- Results
- You write thisState what the graph shows in one or two sentences, with numbers.
- Conclusion
- You write thisSay whether the result supports your hypothesis and why you think so.
Display board
- Title and your name
- Question
- Hypothesis
- Materials
- Procedure (with photos)
- Data table and graph
- Conclusion
- What you would do next
Questions judges ask
- What do the straws do?
- Why does a teardrop have low drag?
- What is frontal area?
- What would you change if you did this again?
- What was your biggest source of error, and how did you reduce it?
- Where is this idea used in real life?
- Research question
- How does the shape of an object change its air drag?
- Hypothesis
- If a shape tapers gently at the back, then its drag will be lower than a blunt shape of the same frontal area.
- Variables
- Independent: object shape. Dependent: drag force reading. Controlled: frontal area, fan speed, position in the tunnel
- Methodology
- Measure drag at three fan speeds and test whether it grows with speed squared.
- Data collection
- You write thisSay what you will record, how many times, and how you will keep the records safe.
- Analysis
- Bar chart of drag for each shape
- Limitations
- You write thisList what could have affected the result: small sample, instrument limits, things you could not control.
Literature review
Find five to eight sources (your textbook, review articles, reports) and note what each says about your question. Group them by idea, not one after another, and end with what is still not known.
References
List every source you used in one style throughout (author, year, title, where it was published, link and the date you opened it).
Working as a team
2–3 people. Suggested roles:
Report and presentation
Report structure
- Title and aim
- The problem it solves
- How it works (principle)
- Parts list with cost
- Design: drawing, circuit or block diagram
- Build steps
- Testing and results
- Problems faced and fixes
- Limitations
- Future improvements
- References
Presentation structure
- The problem
- The idea
- How it works (one diagram)
- Parts and cost
- The build (photos)
- Live demo or video
- Test results
- What did not work
- Next version
Viva questions
Try answering before you open each one.
What do the straws do?
They break the fan's swirling flow into small parallel streams.
Why does a teardrop have low drag?
The flow stays attached along the tapered tail, leaving a small wake.
What is frontal area?
The area of the shape seen from the direction of the flow.
Why put the fan at the outlet?
Pulling air gives a smoother flow than blowing.
Source and attribution
Original
Written by Technifyed. Free to use for your own school or college project; write the report in your own words. Added 1 Oct 2026.
Similar projects
More Aerospace Engineering projects
Aerospace Engineering + Astronomy and Space
Simulate a satellite orbit
Integrate Newton's law of gravity to draw circular, elliptical and escape orbits.
Aerospace Engineering + Physics
Measure the thrust of a water rocket
Build a static test stand and measure thrust against time for different water fills.
Aerospace Engineering · Flight Mechanics
Design and fly a balsa glider
Build a glider and tune wing position and nose weight for the longest straight glide.
Same tools
Materials, Energy and Other Branches + Agri-business and Food Science
Design a solar dryer for farm produce
Build a cabinet dryer and compare its drying time and quality with open sun drying.
Agri-business and Food Science + Biology
Test how storage affects fruit and vegetable shelf life
Store the same produce in five ways and record weight loss and spoilage.
Crops, Soil and Horticulture · Soil Studies
Study the effect of mulching on soil moisture
Compare how fast pots with straw, plastic, gravel and no mulch dry out.
Agri-business and Food Science + Environmental Science
Estimate food waste in your household or canteen
Weigh food waste daily for two weeks, sort it by cause and test one way to reduce it.
Two-subject alternatives
Physics + Programming
Simulate projectile motion with air drag in Python
Plot real trajectories with air resistance and compare them with the textbook parabola.
Environmental Science + Electrical Engineering
Build a wind turbine and find the best blade design
Build a small wind turbine on a DC motor and test how blade number, angle and length change the voltage.
Robotics, IoT and Hardware + Mechatronics and Robotics
Build a line-following robot
Build a two-wheeled robot that follows a black line using infrared sensors.
Entrepreneurship + Mechanical Engineering
Design a business around a science fair invention
Take a working model you have built and work out who would buy it, at what price and at what cost.
Same difficulty and budget
Industrial and Manufacturing + Operations, HR and Supply Chain
Analyse and reduce waiting time at the canteen
Time each step of the canteen queue, find the bottleneck and test one improvement.
Mechanical Engineering · Machines
Design a gearbox and measure its speed ratios
Build a two-stage gear train and check the measured ratio against the tooth counts.
Electronics and Communication + Data
Filter noise from an audio recording
Record speech with a hum, find the hum's frequency and remove it with a digital filter.
Civil Engineering + Earth Science
Design an earthquake-resistant building model
Build a simple shake table and test how bracing and base isolation protect a model tower.