Optimization of Riblets on Bicycles Jason Ryan Image Source Image - PowerPoint PPT Presentation

Optimization of Riblets on Bicycles Jason Ryan

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Project Summary • Goal ▫ Validate the concept of using aerodynamic riblets to reduce drag on a bicycle • Outcomes ▫ Quantify the drag reduction from applying riblets in the flow regime experienced by bicycles ▫ Determine the most influential riblet parameters for drag reduction

Customer Needs Customer Importance Description Need # CN1 1 Reduce drag on the bicycle CN2 1 Retain function as a bicycle CN3 1 Quantify the drag reduction on bicycles due to the application of riblets CN4 1 Determine the most critical riblet parameters for drag reduction CN5 1 Process to construct prototypes needs to accommodate multiple designs CN6 1 Prototypes should be able to meet tolerances CN7 1 Measure drag on the bicycle CN8 2 Be able to measure wind speed and characteristics while measuring drag CN9 2 Non-abrasive to rider CN10 2 Material needs to be durable CN11 2 Weather resistant CN12 2 Low cost

Benchmarking From Research Articles Reynolds Riblet Height Skin Friction Total Drag Number (in.) Reduction (%) Reduction Nasa SuperSonic 2-3.4 million 0.003 4-8% - Test 1 (Source) Nasa SuperSonic 3.6-6 million 0.0013 4-15% - Test 2 (Source) National 3.5-6 million 0.033-0.152 5-8% 2-3% Aerospace Labs (Re/ft) (mm) Report (Source)

Engineering Analysis 1. Drag from Frontal Area Change (0.45%) 2. Reynolds Number (1.76 x 10 4 – 9.4 x 10 4 ) 3. Dimensional Analysis Air to Water 4. Force Concentrations from Riblets

Potential Concepts- Riblet Design Image Source

Potential Concepts - Prototype Image Source

Potential Concepts - Measurement Image Source Image Source

Staffing • 3 ME ▫ Aerodynamics ▫ Data Aquisistion ▫ Materials • 1 ISE ▫ Materials / Manufacturing • Sayer Murphy ▫ ID Student