New Microsoft Flight Simulator – Aerodynamics, Core of Simulation, Sloped Surfaces, Integration System [Video]
Hi i’m Sebastian Wloch CEO of Asobo studio, and today we’re going to talk about aerodynamics. When we started working on Microsoft Flight Simulator, we first studied all the code that has been written on Flight Simulator, Flight Simulator X. There’s been many many years of work on all the code base and The code base of the simulation of the aerodynamics was pretty huge. I will cover five areas of improvements that we made to the flight simulator aerodynamics and physics. First, we made improvements to the core simulation engine. Second We made improvements to the actual simulations of the different systems of the aircraft. Then the thing the biggest area we worked was the aerodynamics we reworked our dynamic simulation from scratch in the simulator. I’m gonna go over the details of how the aerodynamic simulation now works. One big area that we reworked was the weather system. The biggest interaction of the aircraft is with the air. It’s the air that makes the aircraft fly And so we reworked how the air was simulated in the world really creating a full Simulation of the airflow over the planet and I’m going to explain how the air flow interacts with the world the environment and also with the weather.
The first big improving way to the core of the simulation is a better collision model with the environment. So the system now supports sloped surfaces, which means that aircraft can land on sloped runways, but also on any slope in the world aircraft can now land on the slope field. For example if you wanna simulate an engine failure you can make a cross-country landing on any surface including sloped surfaces like fields on mountain slopes, it can work anywhere. To make slope surfaces work? We had to rewrite the friction model of the aircraft. So tires are now correctly simulated with dynamic friction, static friction, all the friction parameters have been improved and so like the rubber now really behaves on all different surfaces like tarmac, cement, grass, earth exactly like it should, and also on slopes if the tires start to skid they’re gonna skid exactly like they showed with realistically simulated dynamic and static friction. So we also improved the way the bumps on the ground are handled there now realistically Simulated and the way the brakes are simulated. So this allows for planes to come to a full stop even on slopes and that’s when they transition from dynamic friction to static friction and planes can really come to a complete halt exactly as they should on slopes. So when you do landing on a sloped runway you can now roll and you can stop on the slope, turn around and take off again.
We also rewrote the integration system of the simulation. So the integrator is what makes the simulation go forward. It calculates all the states of the system. So one thing we changed is now that the simulation is running at a much higher frame rate. But the frame rate is adaptive. So it adapts to the frame rate of your actual TV or monitor. This means that the simulation is much more smooth. Whatever the frame rate of your display even if you have slower frame rates, frames are exactly going to match the display. And also the simulation is always gonna run at a higher frame rate. So even if your frame rate goes down, the simulation stays at a high frame rate and you don’t lose anything of the realism, planes always behave as they should whatever the frame rate. Another big change we made to the integrator is the way the integration now works. It’s much more realistic and it has removed one artifact that was present in previous versions of flight simulator which is that planes felt like if they were on rails. it’s because the old integrator was resisted resisting change and it was forcing planes to always move more less in a straight line. So the integration is now super realistic. It’s exactly moving the aircraft as they should in the world spins are not much more realistic now and planes don’t feel on the on rails anymore.
So we change that and remove the effect of planes being on rails. We also reworked the inertia matrices. They are now more realistic which means that the mass distribution of aircraft feels more real and planes when they rotate when they yaw, when they pitch, when they roll They feel much more realistic now as they as they travel through air. So we also made improvements to systems in the simulation other than aerodynamics.
We improved the load factor simulation, which also improved the way the ball the turn coordinator simulated. It’s now much more realistic, which means that when you fly asymmetric, which means that if your aircraft skids a little the ball is, is moving to the side exactly as it should and you can now control With the rudder your flight and make it symmetric using the ball much more Easily because it reacts much more realistically than before. And so we have now specific fuel consumption which is realistic altitude level and which is matching the actual poh of the aircraft. We improve the way flaps can be set in the files which allows to have more control. We finally re-worked the way gears and external parts, like external tanks are simulated instead of just hard coding the moments they apply on the aircraft they are actually physical elements in the airflow which are attached to the airframe outside of the aircraft and they now realistically simulated aerodynamically just like the aircraft and apply their own forces and moment exactly where they should how they should.
We also improve the icing system so icing is now simulated to realistically depending of the actual humidity of the air around the aircraft and because the weather system is now accurate and simulated volumetrically if you fly through clouds. You’re going to get a different icing than if you fly through dry air and so this is now simulated in 3d volumetrically also what we did is the legacy simulation code from Flight Simulator x is still available so you can Switch to the legacy simulation. If you don’t like the new simulation, we don’t want to force anyone to move to the new simulation so all aircrafts have been reviewed with professional pilots who have many hours flying these aircrafts or test pilots from the manufacturers so we’ve gone over the aircrafts and which were already matching poh when we presented them but to make sure they actually are controlled exactly like they should There’s many parameters that we said that are not actually present and poh such as how fast the aircraft is gonna roll when you move the the yoke to the left, for example, depending on your airspeed this is data that is not always available, but that professional pilots feel they know how agile the plane is at what speed and so these are parameters that we set with them and we reviewed the whole aircraft to make for example stalls at Or if an aircraft can spin or not or the way, basically They behave so that they don’t just match Performance parameters from the poh but actually feel as the real aircraft when you fly them in real life.
So the big change we made to the system is the aerodynamic stimulation has been reworked how we simulate now is much more advanced. So we subdivide the aircraft and to thousands of surfaces which are mapped over the airframe So for example over the wings over the fuselage over the wheels over the tail There’s thousands of little surfaces which are placed exactly where they should over the geometry of the aircraft Each surface goes look at the weather. So it has its own wind direction It’s going to have its own air pressure. Its own humidity This means that the right wing for example can fly through a cloud where the left wing doesn’t and you can have different Wind turbulence and humidity on the right wing each of these surfaces has a realistic air flow simulation Each surface is going to have its own wind direction its own air pressure and it’s going to do a full three-dimensional calculation to compute.
What is the force and moment that should result from the air flow flying over the surface? The simulation includes the air flow speed and detachment and orientation It will realistically simulate stall the stall is when the airflow is Actually bent too far by the surface and the air flow cannot stay attached to the air surface anymore So this is now simulated surface by surface, which means that we can have a left wing stalling Especially because of the weather and the full realistic simulation of each surface in the world But each surface will also deflect will also deflect the airflow The airflow is going to be impacted and surfaces which are behind are going to get a different air flow Because the airflow was impacted by the surfaces in front So this for example is going to allow more aerobatics so for example the airflow is coming from the propeller and is hitting the tail and that’s how you can for example enter into a flat spin or some of the figures So for example when you could do inverted spin, that’s because the propeller hits the tail and this is now realistically simulated The big main improvement we made to the simulation is the simulation of the air mass We now simulate the air mass globally or the entire planet and realistically every area of the world has its own simulation of air And we know where the air is flowing Everywhere on the planet and this then feeds into the aerodynamic system of the surfaces of the aircraft. So this means that for example We will have volumetric clouds which you can see in the world which are going to match the airflow for example on TCU’s on towering cumulus Clouds usually it’s a kind of cloud which exists because there’s a lot of updraft of air But when they get really big there’s updraft on the side and in the middle, it actually goes down That’s basically why they are so dangerous and you should never in a small aircraft get close to TCU in a big aircraft You’re gonna get a lot of turbulence And so this is now simulated the air flow in the world is going to match the clouds and it’s going to fly the air is going to move up and down inside of the clouds. So you will see a video which is going to show this air flow So in order to visualize the air flow We release thousands of particles in the world and displayed. The trajectory of the particles and they just do exactly the same calculations than the aircraft in the world. So each particle samples the world atmosphere exactly like each surface on the aircraft so you can see on clouds. That the air is moving up and down and you can see the turbulences which is when the airflow of the particles changes colors. And the particles move more randomly. So these are like wind shear or turbulences. Some of the air may go up because it’s in the middle of the cloud some may go down and at the edges you get. Shear so this is all now naturally simulated and we have all the updrafts and downdrafts. In the world which match which match actually the weather. So this simulation also works with the world shape like the shape of the world. Which can depend on buildings, hills, forests, mountains, valleys. So all these different shapes worldwide are going to influence the air flow in the world. So for example, the air flows over a stadium or a hill it’s going to create updrafts. So the wind is going to flow up and on the other side. Usually there is it goes back down but in a turbulent way, right it it has to go back down But it’s gonna be creating a lot of rolling turbulences. So you can imagine when you fly over this air with the aircraft if the aircraft is flying slow if it’s a small aircraft It’s gonna get all these rolling moments. It’s going to get the up-and-down raft and you’re gonna feel all these bumps So on the video you are going to see there’s for example wind flowing over mountains And it naturally creates turbulence’s on the other side in the valleys where the currents come together They collide and it creates these turbulence as you can see in the in the middle of the valley you can see the up-and-down draft and You can see how the the slope of the wind is actually very very steep. Right it goes it goes along the slope. So this is it for the improvements on the aerodynamics on the physics. So we improved the core simulation or improved many of these simulated systems. We reworked the aerodynamic simulation with the surface based system and we reworked the simulation of the airflow in the world all these changes. Come together to create a much more realistic simulation of the aircraft aircrafts and all simulated realistically to the performance data That is available. They fly exactly to the real-world performance, but they also feel exactly like real aircraft they turn they behave when you move this yoke exactly like a real aircraft and They fly through the world they fly through the air Exactly like a real aircraft flies through the air in the real world being impacted by clouds by mountains. By buildings by the shape of the world right. I hope you enjoyed the details I gave about the simulation about what we changed. Thank you for your time please subscribe to the Alpha and Talk to you soon.