Temperature and Performance

While in the Air Force I have been to many different places with my AMU and one thing i have always noticed as when out jets would take off at Las Vegas versus taking off at Alaska, they sound like completely different machines.  In 95 degree heat they sounded dull and un-energetic, however on the other hand, in 30 degree temperatures, they scream and sound like a dying animal!  So is it just sound or is the engine actually performing better?  

As I was going through our weekly reading I came across chapter 11 which directly relates to aircraft performance.  What reading about density i read the temperature and density directly correlate.  The colder it is the more dense the air is and vise versa with hot air making the air less dense.  This mean that say the engine ideal combustion ratio is 15:1, meaning you need 15 parts air for every 1 part of fuel.  While reading an article it explained "cold air molecules move slower and collide with less energy than hot molecules, causing cold air to become more dense. As temperature drops, more air molecules enter an engine, and as temperature rises, less air molecules enter an engine"(Cutler, 2013, para 1).



So in short, the reason they sound like difference machines is because they are operating and performing differently.  When its colder, the engines are using more fuel and there for making more power versus during hot water.  Its just like a turbo charged car, you could drive the same car with the same gas but only change the air temperature, and could increase or decrease power.  

Reference:

Cutler, C. (2021). Chilling Performance: Why Aircraft Engines Generate More Power in Cold Weather. Boldmethod Flight Training. Retrieved 5 November 2013, from https://www.boldmethod.com/blog/2013/11/how-cold-air-affects-engine-performance/

Comments

  1. Dr. Amaya DavisNovember 30, 2021 at 4:46 AM

    Very interesting and great idea showing a pic of the differences between temperatures!

    ReplyDelete

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