Questions tagged [aircraft-physics]
Physics as they apply to aircraft. Including aerodynamics, flight dynamics, stability and control, aircraft hydraulic and electric systems, engine thermodynamics.
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Why isn't the rudder below the tail?
Most airplanes have a rudder on top of the tail. When it is turned to the left, it causes the plane to yaw to the left. But it also puts a roll force to the right, because it is usually above the ...
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Yawing during turns
This is a question about aeronautics. Does an airplane yaw while it is turning?
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Why does the F/A-18 use external aileron and flap hinges?
As seen in the picture, the legacy Hornet uses ailerons and flaps with external hinges, and I was wondering what were the advantages of external hinges compared to flush hinges in the land-based ...
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Deriving Accurate Exit air velocity of rotor
My goal is to derive the equation for exit air velocity as a function of:
Pitch angle
RPM
Rotor Radius
Constants like ρ
Assumptions:
Vc is relative velocity of air upstream, and is = 0
Inflow is ...
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Is the Lift required for a steady-state climb and descent equal for the same absolute value of the kinematic climb angle? [duplicate]
Here is my confusion :
I found in my lecture script the following equation for the steady-state climb and descent (wings level)
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Is the Reference Speed (Vref) the same as the speed at which the aircraft cross the runway threshold in landing phase?
Just a little confuse when I learned about the aircraft classification based on approach speed. Can anyone help me to have an accuracy look about this question?
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Does pilot need to increase thrust when gust hit him at landing and where is axis of rotation?
Let's say a plane is flying above a runway in straight line, and gust of wind hits the plane from side.
Do pilot need increase thrust to stay above runway and where is axis of rotation ?
It often said ...
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Do airliners respond to mild turbulence in real time?
I've always been fascinated with the impact of ailerons on an aircraft's trajectory; from what I have seen sitting by a wing is that the slightest movement can bank the aircraft quite significantly.
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Why do newer engines have such wide fan blades?
Every treatise I read about propellers/fan blades/wings states that long, thin wings are more efficient than wide stubby ones.
So why is it that the blades in high-bypass turbofan engines fitted to ...
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Flying upside down without feeling it
A friend of mine told me that several years ago she flew on a two-seats general aviation aircraft. She does not remember the exact model, but she remembers well that the pilot flew upside down for a ...
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Do fuel tanks need to be pressurized?
Do fuel tanks need to be pressurized? It's my understanding that the pressure difference between the outside air and the inside fuel would force the kerosene out of the fuel tank. What stops this from ...
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How does elevator control effectiveness change with altitude/ air density?
Suppose an unpowered, rigid, mechanical, lightweight aircraft (e.g. sport glider) is descending at a steady glide in a constant trim (hands off) configuration in a standard atmosphere. The pilot ...
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Why will all air slow down by the same amount in an adverse pressure gradient?
Boundary layer separation is caused by air slowing down to zero and reversing before reaching the end of the body. This is due to friction (viscous effects) + adverse pressure gradient.
The formation ...
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How does momentum thrust mechanically act on combustion chambers and nozzles in a jet propulsion?
I'm asking this question since I can't intuitively understand how the acceleration of mass flow and therefore the increase of its momentum can actually mechanically act on the combustion chamber ...
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Why does bank angle have no effect on pivotal altitude?
Pivotal altitude is the height for a given ground speed at which the line of sight from the cockpit directly parallel to the lateral axis of the aircraft will remain stationary on an object on the ...
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Does the cross-sectional shape of a fuselage affect drag?
Comparing two bodies with the same streamlined longitudinal shape, and the same cross-sectional area, one with a circular cross-sectional shape, the other with a quadratic cross-sectional shape, ...
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What are the flight formulas for aircraft
I am making a 2D flight "simulator" (trying to be as realistic as you can for 2d) and I need flight formulas for lift, speed and pitch. I have tried a few sites but I do not understand what ...
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Anyone knows where i could find the McMaster, H. C., “FAR 23 LOADS”, Aeroscience Software, 2.02 Edition?
I am currently conducting research on wing lift distributions and came across the existence of a software tool called "FAR 23 LOADS," developed by McMaster, H. C. (Aeroscience Software, 2.02 ...
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Why aren't Biplanes designs used when size and wing span restrictions are involved? [duplicate]
This research paper shows that for a given aspect ratio and wing area, compared to a monoplane a biplane produced a better L/D. So, wouldn't it make more sense to manufacture biplanes for subsonic ...
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How can the effect of wind gradient in a glide be calculated?
If an airplane glides in a mass of air where the headwind changes with altitude, it seems logical to think that the length of the glide –as measured by a ground-based observer– will be longer in the ...
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Energy Maneuverability Theory Applied to WW1 Fighters
I am trying to test the Fokker D.VII, Spad S.XIII, Sopwith Camel, Nieuport 28, and the Se5a using the model in this paper:
https://apps.dtic.mil/sti/pdfs/ADA066034.pdf
It's called Combat Performance ...
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How does a zero g aircraft work?
In upward motion, drag and gravity is in the same direction (both in downward direction). So in this situation G is negative or less than 1 or something else?
In downward motion with thrust greater ...
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Lateral location of the center of pressure
I am working on a simple flight simulator. For this, I need to calculate aerodynamic forces and apply them to the aircraft. As I understand it, lift and drag act through the wings center of pressure.
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How does propeller length, pitch, and airspeed affect efficiency? [closed]
tl;dr: trying to find propeller efficiency with thrust, velocity and power and see which propeller length to pitch ratio is efficient.
Hello, I'm a high school student working on an extended essay for ...
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Center of Gravity, Aerodynamic Center and Center of Pressure, how do they connect?
I read an article that described static margin by taking the aerodynamic center and the center of gravity. It explained why the center of gravity has to be in front of the aerodynamic center for a ...
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Cruising at the speed of sound
Is it possible or feasible for an aircraft to continuously cruise at the speed of sound? Is the drag at this point higher or lower than in the high Mach 0.98 or Mach 1-1.2 region?
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aerodynamic forces on an engine cowling
In Mendenhall's book about the Gee Bee racers, he describes that on the Models Z, R-1, and R-2, there was a strong tendency for the engine cowl to get pulled forward and into the prop during races, ...
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How can I determine the fuel temperature in the tanks of an Airbus A320 during climb?
I know that, for example, at 10000ft the outer temperature is around $-10\, ^\circ\! C$.
How can I calculate the fuel temperature in the tanks?
In technical notes I find on the internet for Airbus ...
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Between hover and moving straight forward, which one is this Sikorsky uses more power?
Source:
Consider this Sikorsky–Boeing SB-1 Defiant is being flying forward level and straight and being hover, which state is consumes more power? For both states, we assume that air is very still and ...
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Examples of jet turbine values for combustions, fuel flow, Q of fuel, temp of exhaust, etc. for classroom use
I am trying to build jet turbine examples for a class and I want to use actual values for the mass flow of fuel and air, combustion temps, exhaust temps, exhaust composition (CO, CO2,H20,o2, NOx) ext…
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Is the same working principle of a vacuum ejector (fluid eductor, pressure ejector or "motive flow") viable to be used as a propulsion system? [duplicate]
Some time ago I've made a question involving Jetoptera bladeless propulsion, and got a comment saying they didn't know how that method of propulsion would make any difference. But I forgot to ask more ...
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what is acceleration of gravity in free fall situation with air drag? [closed]
consider a ballistic missile in reentry trajectory with initial velocity of 1000 m/s. as missile enters the atmosphere, air drag decelereting its velocity so missile's acceleration becomes negative. ...
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Does optimum IAS for climb vary with altitude?
I was in an argument about aerodynamics and we eventually derived an equation as follows.
So I'm going by this equation:
$$RoC = \frac{\eta_p P-VD}{W}$$
Where $\eta$ represents propeller efficiency.
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How is rotational dynamics related to navigation?
I've been learning how to do dead-reckoning using just an ordinary IMU chip (a 3-axis accelerometer and a 3-axis gyroscope). In a number of textbooks I've read on aircraft navigation, the motion of a ...
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Is it possible to fly with lower than 1 g-force?
I was watching this video GOING SUPERSONIC with U.S. Air Force Thunderbirds! and at some point (video 15:20 minute) the g-force appear to be 0.7. Here image from the video:
As you can see the g-force ...
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Can you drop the bombs of an F-16 during 9G-forces?
An F-16 simulator instructor told me that it is not possible to drop the bombs of an F-16 during 9 G-forces. I was surprised by this fact and looked it up, but I couldn't find anything about this. So ...
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What makes the MV-22 has lift thrust and its disk loading is so high?
Image source:
The above is comparison table of several rotating wing aircraft's disk loading, especially I highlighted the disk loading of MV-22 Osprey tiltrotor versus CH-47 Chinook helicopter. As in ...
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How does the V-280 Valor maintains its Center of Gravity (CG) when it is converted from helicopter (hover) mode to plane (flight) mode?
Picture source:
The above pictures are showing three modes of V-280 Valor: hover or VTOL/hover mode, transition mode from VTOL to flight, and flight/air plane mode. As we may see, there is a CG ...
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Why does this V-22's rotors rotate clockwise and anti-clockwise (the right and the left rotor respectively)?
Picture source:
By seeing the blades, we know the rotation's directions. The right side is clockwise and the left side is anti-clockwise. Both seen from the pilot/rear side. During the cruise, the ...
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is aircraft weightless during vertical climb?
in vertical climb , if velocity is constant (no acceleration) the pilot feels 1g gravitational acceleration that is equals for crusing flight. but in vertical climb lift must be zero so load factor is ...
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load factor in high altitudes
if load factor equation is lift devided by weight , so in very high altitude for example 1000 km above the earth atmosphere, there is no air to produce lift so load factor is zero but in newton ...
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How to calculate lift/thrust effect of adding blade to a propeller?
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Say I have blades of a propeller of an aircraft (airplane or helicopter). The blades have exactly the same profile, size, dimension, and weight, and will be coupled to a shaft with the same ...
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Why astronauts during launch fly faster than jets but experience less Gs? [closed]
The NASA Space Shuttle used to lunch astronauts into spaces at high speeds, supersonic speeds. When you google whats the Gs force they experienced while departing or simply “Gs forces astronauts” You ...
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Why do fighter jets make a whistling noise when landing and taking off?
Lately, I was watching fighter jets (F-16s and F-35s) from very close (fascinating!) and heard for the first time the "whistling noise" when they were landing and taking off. I expect it has ...
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what exactly Vx and Vy for in gliding and powered descent(piston-prop aircraft)
as i understood,for a prop-piston aricraft :
during a gliding, through the equation:
tanγ= D/W≈ 1/K
sink rate≈ VD/W≈ V/K
by which we get(theoretically):
Vx(Vmp) is the speed at which we get minimum ...
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How to calculate optimal flight climb angle?
I am trying to calculate the optimal flight climb angle based off of some basic power calculations for an aircraft on steady climb with an angle of theta. Doing a balance of forces I obtained the ...
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Do aircraft pitch down even at very low angles of attack (below 0°) in a strong sideslip?
I was doing an analysis of an aircraft (specifically the PZL Koliber 160 with the NACA 63A416) strong sideslip conditions (beta=30° for example) in OpenVSP at various angles of attack, and observed ...
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RPM of wheels on touchdown
What is the average RPM of the wheels of commercial airplanes upon touchdown?
I understand there is variability that comes with different wheel sizes, approach speed, etc. Just thinking of the average ...
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What fraction of fuel is consumed just for keeping a plane in the air?
In a typical airliner, what fraction of fuel/power/energy is used for providing lift and overcoming lift-related drag
Do the density of the air and the speed through it influence this ratio or do they ...
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for a piston-prop aircraft, why "V max excess power" equals Vmd and "V max excess thrust" equals Vmp?
as what i read from books, on thrust-velocity and power-velocity curves for a piston-prop airplane
V max excess power= Vmd
V max excess thrust= Vmp
these two values are just so clicking, and i ...
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