Articles on the science behind aerodynamics.
Engineering Design with AeroLab
April 3, 2018
Despite what you may have been told by your teachers / instructors / professors, the concept of an ‘exact’ solution to an engineering design problem often does not exist. Engineering design solutions are frequently a result of compromise between competing objectives, e.g., aerodynamics, weight, stiffness, cost, etc.
Power Meter Data Quality & Real-Time CdA Measurements
March 12, 2018
What accuracy and precision in power meter measurements are acceptable for computing aerodynamic drag? This is the focus of the current article. If you have not already done so, please see our first two articles on Rider Weight and Rolling Resistance. Recommendations have been made for real-time aerodynamic testing.
Can Rolling Resistance & Rider Weight be Assumed Constant, pt 2
January 29, 2018
When using Aerodynamic Sensors on a bicycle for the purpose of estimating CdA, the total weight of the rider must be known within about 0.5 [Kg] or better, the rolling resistance coefficient Crr should be either known or measured with significantly better than 10% accuracy, and calibration bias in power meter measurements should be significantly less than 2% of the measured power.
Can Rolling Resistance & Rider Weight be Assumed Constant, pt 1
January 27, 2018
In real-time aerodynamic drag and coefficient of drag calculations, it is important to have a good estimate of the rider weight, the rolling resistance coefficient, the power input to the pedals, the wind velocity, and environmental factors. For instance, when selecting a power meter, consumers have an expectation of ‘good’ accuracy. What is not clear, is the quantitative definition of ‘good’ for aerodynamic calculations.