Learning Forum

[zhang_zongwei]

 I encountered a problem in an Ansys Fluent tutorial involving buoyancy and a blimp example. The tutorial video mentions that the blimp, floating in the air, experiences an upward buoyancy force of 0.1923 N. The blimp contains hydrogen, which has a weight of 0.0255 N, and the weight of the blimp's sides is 0.008 kg.

The video indicates that this blimp can lift an additional 160 grams, but when I performed the calculation myself, the results differed.

My Calculation:

1. Calculate the Weight of the Sides: Convert 0.008 kg to Newtons to consider the gravitational effect: 0.008 kg×9.8 m/s2=0.0784 N0.008kg×9.8m/s2=0.0784N
2. Calculate the Total Weight: The total weight is the sum of the hydrogen's weight and the weight of the sides: 0.0255 N+0.0784 N=0.1039 N0.0255N+0.0784N=0.1039N
3. Calculate the Blimp's Load Capacity: The load capacity is the difference between the buoyancy force and the total weight: 0.1923 N−0.1039 N=0.0884 N0.1923N−0.1039N=0.0884N
4. Convert Load Capacity to Mass: Using the gravitational acceleration (9.8 m/s²), convert the load capacity from Newtons to kilograms: 0.0884 N÷9.8 m/s2≈0.00902 kg≈9.02 grams0.0884N÷9.8m/s2≈0.00902kg≈9.02grams

My Question: According to the above calculation, the blimp's load capacity is about 9.02 grams, while the tutorial video claims that it can lift an additional 160 grams. What could cause this discrepancy? Could my calculation process or understanding be incorrect, or might the 160 grams mentioned in the video refer to something else? I would appreciate any assistance or clarification on this matter.

Please check the video with this link 

https://www.youtube.com/watch?v=tKaZp6RyaH8&list=PLtt6-ZgUFmMKJW55IFsfpZaNU2sG27so4&index=5

 

[Sunil Lilhare]

Hello! Thank you for bringing this to our attention. We are currently reviewing the issue you have reported and we will get back to you once it has been resolved.