Recent content by JME23

Thanks again CWatters and everyone else. I think I'm not so much saying that the tips cause downwash so much so as that is where I believed it to occur as that is where the air is able to escape to the upper surface creating the vortices. The downwash being at its greatest at that location and...

Thanks everyone for your inputs. I do feel guilty that I am still scratching my head. Having just quickly recapped on what causes downwash on a wing -the vortices at the tips of the wings where the air spills over from the bottom surface to the top and spreading over the span of the wing. Is...

hmm. That's a tricky one. I wouldn't expect any air to move to the left (I suspect by you mentioning to ignore vortices that could have carried some air back, but even them I'm not sure). Any king of body moving through air must carry some air with it (more intuitively in front rather than...

That definitely helps, anorlunda. So is it safe to say then that the rearward flow is created in the same way as downwash?

Yes BvU. I've always assumed this was less of an aerofoil shape and more of a reaction type blade. This is slightly more intuitive to me as I can imagine how the acceleration is transferred from the blade to the fluid in this manner. It's when it becomes an aerofoil that I get confused. That's...

Thanks also boneh3ad. So is the airflow which opposes the thrust on a propeller (that I'm struggling to grasp) directly analogous to the downwash on an aircraft wing?....and as you say the shape of the blade is key. If a propeller blade was made of the same cross section of a wing (scaled...

Thanks for the reply Scott. That is however the only bit i do understand. It's the part where the air is sent rearwards that is the sticking point with me. I assume there is also a downward motion of air on a regular wing but that isn't something discussed when looking into basic aerodynamics so...

Hi, Could someone please help me in understanding how the air is thrust rearward by a propeller? I am specifically interested in how an axial-flow compressor, which uses aerofoil shaped blades to force the air through the engine does so, however I feel a good start is a propeller. It makes...

Thank you both for those links. I trawled wikipedia and couldn't find anything as relevant as those explanations. The answer to the above question I came across in my practice test does then result in that answer given which I first doubted. The explanations given here are far more convincing...

Hi There, Can anyone please help with the attached diagram of a cooling system? In particular the role of the compressor. I understand what happens at each stage but I am keen to understand why. The Hot Airflow passes the Flow Control Valve and some passes through the Primary Heat Exchanger...