Aero Basics -2
The previous update on this section was made almost a year ago- really time flies so fast :P .
This section continues with another set of aspects related to "aeroplanes"
Motion Relative to Air and Relative to ground:
This is a basic observation from first chapter of common physics book(HC Verma examples) on "Relative motion"
The philosohpy is :
"The actual path and speed of an aeroplane relative to ground ,depends on the wind speed and wind direction relative to ground."
What I am really concerned is with how much does this affect small sized micro-air vehicle and in manual control I guess our brain and eyes form a feedback network which takes care of the motion without us really bothering about it.Thus, I feel if I am making a autonomous micro air vehicle will the calculation of this aspect actually come into play.
Wind Tunnels:
From a real sized plane point of view to analyse a design and predict the real case scenario , wind tunnels are constructed with simulate wind conditions.
Now generally wind tunnel tests are done on small sized models and then appropriated applied to real sized planes.The laws of scaling here breakdown when the plane is moving at very high speed and when its really large.This is known as "scale effect " and a measure of deviation from approximation to that seen on the model is measured by "Reynolds number".
Difficulties:
What is really difficult to do in a wind tunnel, is to achieve the wind speeds actually encountered by the plane.Also the effect of scratches on the wing surface and the details of the small parts can't be modeled exactly using a small model.
Also in a normal wind tunnel, since air is transparent, the actual motion of wind around the structure can't be visualized.
To overcome former difficulty, one way out is using compressed air tunnels.
This section continues with another set of aspects related to "aeroplanes"
Motion Relative to Air and Relative to ground:
This is a basic observation from first chapter of common physics book(HC Verma examples) on "Relative motion"
The philosohpy is :
"The actual path and speed of an aeroplane relative to ground ,depends on the wind speed and wind direction relative to ground."
What I am really concerned is with how much does this affect small sized micro-air vehicle and in manual control I guess our brain and eyes form a feedback network which takes care of the motion without us really bothering about it.Thus, I feel if I am making a autonomous micro air vehicle will the calculation of this aspect actually come into play.
Wind Tunnels:
From a real sized plane point of view to analyse a design and predict the real case scenario , wind tunnels are constructed with simulate wind conditions.
Now generally wind tunnel tests are done on small sized models and then appropriated applied to real sized planes.The laws of scaling here breakdown when the plane is moving at very high speed and when its really large.This is known as "scale effect " and a measure of deviation from approximation to that seen on the model is measured by "Reynolds number".
Difficulties:
What is really difficult to do in a wind tunnel, is to achieve the wind speeds actually encountered by the plane.Also the effect of scratches on the wing surface and the details of the small parts can't be modeled exactly using a small model.
Also in a normal wind tunnel, since air is transparent, the actual motion of wind around the structure can't be visualized.
To overcome former difficulty, one way out is using compressed air tunnels.