▲ 167 ▼ What was a fact taught to you in school that has been proven false during your lifetime? (lemmy.ca) submitted 1 year ago by Kurtagag@lemmy.ca to c/asklemmy@lemmy.ml 204 comments fedilink hide all child comments
[–] Dirk@lemmy.ml 22 points 1 year ago (2 children) How planes generate lift. permalink fedilink source hideshow 4 child comments replies: [–] helix@feddit.org 13 points 1 year ago (3 children) Did they finally find that out? Last time I checked even PhDs in aerospace engineering still added "we think" at the end of their explanations. permalink fedilink source parent hideshow 6 child comments replies: [–] ImplyingImplications@lemmy.ca 18 points 1 year ago NASA has a webpage on aeronautics that says lift is the mechanical force created by a solid object turning a flow of liquid or gas. They also have an equation for calculating lift for any solid object/fluid combo. permalink fedilink source parent [–] BCsven@lemmy.ca 4 points 1 year ago The wing experiment with hundreds of pressure sensors shows lower pressure on top and more on bottom. permalink fedilink source parent [–] Tungsten5@lemm.ee 4 points 1 year ago* (1 child) It is known yeah. Another user commented it. If you take a wing and put it in a wind tunnel you can put sensors in its wake to measure the pressure. By manipulating the fluid flow you can change the pressure. So low pressure on top and high pressure on bottom. Multiply that by the surface area and you get a force. Smaller force on top of the wing, lower force on the bottom of the wing. So the wing goes up. Of course theres some physics going on in the fluid that explains the change in pressure, but this is just a quick and simply-put explanation because I took a fat amount of zquil and am tired. Source: Im getting a PhD in aerospace engineering Edit: I had to do this in a wind tunnel during one of my undergrad courses. It was fun playing with the wind tunnels, would recommend permalink fedilink source parent hideshow 2 child comments replies: [–] helix@feddit.org 1 point 1 year ago* hm, I just read through a few publications pertaining the Navier–Stokes equations and the scientific community still didn't seem to find out why they're not 100% accurate even in lab conditions because of threedimensional interference, is that correct? permalink fedilink source parent [–] LainTrain@lemmy.dbzer0.com 2 points 1 year ago What doesn't help is that plane pilots are basically taught a different version of physics to spare them from liquid dynamics and to see the forces on an aerofoil as independent ones which makes it all pretty confusing for a layperson trying to get a basic understanding of both and marry the two permalink fedilink source parent
[–] helix@feddit.org 13 points 1 year ago (3 children) Did they finally find that out? Last time I checked even PhDs in aerospace engineering still added "we think" at the end of their explanations. permalink fedilink source parent hideshow 6 child comments replies: [–] ImplyingImplications@lemmy.ca 18 points 1 year ago NASA has a webpage on aeronautics that says lift is the mechanical force created by a solid object turning a flow of liquid or gas. They also have an equation for calculating lift for any solid object/fluid combo. permalink fedilink source parent [–] BCsven@lemmy.ca 4 points 1 year ago The wing experiment with hundreds of pressure sensors shows lower pressure on top and more on bottom. permalink fedilink source parent [–] Tungsten5@lemm.ee 4 points 1 year ago* (1 child) It is known yeah. Another user commented it. If you take a wing and put it in a wind tunnel you can put sensors in its wake to measure the pressure. By manipulating the fluid flow you can change the pressure. So low pressure on top and high pressure on bottom. Multiply that by the surface area and you get a force. Smaller force on top of the wing, lower force on the bottom of the wing. So the wing goes up. Of course theres some physics going on in the fluid that explains the change in pressure, but this is just a quick and simply-put explanation because I took a fat amount of zquil and am tired. Source: Im getting a PhD in aerospace engineering Edit: I had to do this in a wind tunnel during one of my undergrad courses. It was fun playing with the wind tunnels, would recommend permalink fedilink source parent hideshow 2 child comments replies: [–] helix@feddit.org 1 point 1 year ago* hm, I just read through a few publications pertaining the Navier–Stokes equations and the scientific community still didn't seem to find out why they're not 100% accurate even in lab conditions because of threedimensional interference, is that correct? permalink fedilink source parent
[–] ImplyingImplications@lemmy.ca 18 points 1 year ago NASA has a webpage on aeronautics that says lift is the mechanical force created by a solid object turning a flow of liquid or gas. They also have an equation for calculating lift for any solid object/fluid combo. permalink fedilink source parent
[–] BCsven@lemmy.ca 4 points 1 year ago The wing experiment with hundreds of pressure sensors shows lower pressure on top and more on bottom. permalink fedilink source parent
[–] Tungsten5@lemm.ee 4 points 1 year ago* (1 child) It is known yeah. Another user commented it. If you take a wing and put it in a wind tunnel you can put sensors in its wake to measure the pressure. By manipulating the fluid flow you can change the pressure. So low pressure on top and high pressure on bottom. Multiply that by the surface area and you get a force. Smaller force on top of the wing, lower force on the bottom of the wing. So the wing goes up. Of course theres some physics going on in the fluid that explains the change in pressure, but this is just a quick and simply-put explanation because I took a fat amount of zquil and am tired. Source: Im getting a PhD in aerospace engineering Edit: I had to do this in a wind tunnel during one of my undergrad courses. It was fun playing with the wind tunnels, would recommend permalink fedilink source parent hideshow 2 child comments replies: [–] helix@feddit.org 1 point 1 year ago* hm, I just read through a few publications pertaining the Navier–Stokes equations and the scientific community still didn't seem to find out why they're not 100% accurate even in lab conditions because of threedimensional interference, is that correct? permalink fedilink source parent
[–] helix@feddit.org 1 point 1 year ago* hm, I just read through a few publications pertaining the Navier–Stokes equations and the scientific community still didn't seem to find out why they're not 100% accurate even in lab conditions because of threedimensional interference, is that correct? permalink fedilink source parent
[–] LainTrain@lemmy.dbzer0.com 2 points 1 year ago What doesn't help is that plane pilots are basically taught a different version of physics to spare them from liquid dynamics and to see the forces on an aerofoil as independent ones which makes it all pretty confusing for a layperson trying to get a basic understanding of both and marry the two permalink fedilink source parent