Is the Blade Loading Sufficient for Minimum Sliding Resistance at Top Speed?

  • #1
Colin Wilson
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I'm building a model as shown below (side, front, back). In order to measure its air resistance I will be mounting it on temporary ice blades (Green) and driving it down a long skating rink. The model has a pressure sensor incorporated into the motor / propeller assembly and a GPS unit to measure velocity, a microcontroller collects the data (pressure / velocity) and writes it to an SD card. As it sits the blade loading would be as follows:
  • (3) SS blades = 30cm long * 1mm thick
  • Top speed 90kph (82fps)
  • Loading 2kg per blade = 0.67kg / cm2
My question: Is the blade loading high enough given the top speed to ensure minimum sliding resistance? I can add more weight to the model or I can reduce the blade lengths.
DB Slim Test Sled Side.jpg
DB Slim Body Front.jpg
DB Slim Test Sled Back.jpg
 
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  • #2
I searched ice skate friction, and found myself traveling down a rabbit hole of interesting information. But I did not find an answer to your question. You apparently already understand that pressure between the skate blades and the ice is a key variable, as is also the ice temperature.

I suggest that you treat the blade loading as an experimental variable, and run a series of experiments to optimize it.
 
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  • #3
Thank you for your input.
In any case woke up this morning and decided to put pressure sensors on each blade and subtract those readings from the motor reading so problem solved!
 

Related to Is the Blade Loading Sufficient for Minimum Sliding Resistance at Top Speed?

What is blade loading and why is it important for sliding resistance?

Blade loading refers to the distribution of forces on a blade, such as those on an ice skate or a turbine blade. It's crucial for sliding resistance because improper loading can lead to increased friction, instability, and reduced performance at top speeds.

How can I determine if the blade loading is sufficient for minimum sliding resistance?

To determine if the blade loading is sufficient, you can conduct tests that measure the distribution of forces along the blade's surface. Computational simulations and empirical testing, such as using pressure-sensitive films or strain gauges, can provide insights into the adequacy of the loading.

What factors influence blade loading and sliding resistance?

Several factors influence blade loading and sliding resistance, including the blade's material, geometry, surface finish, and the conditions under which it operates (e.g., temperature, speed, and load). Proper design and maintenance are essential to optimize these factors.

Can blade loading be adjusted to improve sliding resistance?

Yes, blade loading can often be adjusted by altering the blade's design, such as changing its curvature, thickness, or material properties. Additionally, optimizing the operating conditions, such as the angle of attack or lubrication, can also improve sliding resistance.

What are the common signs that blade loading is insufficient for top speed performance?

Common signs of insufficient blade loading include increased friction, excessive wear, overheating, and instability during operation. If you notice these issues, it may be necessary to reassess and optimize the blade loading.

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