Recent content by Aleksej

Yes As we try to keep a constant speed of parcels then "the area of the cross-section of the pipe needs to grow proportionally to the decline of density of the gas inside". The pressure is almost equal to outside so the density declines with the altitude as in "normal" atmosphere. The walls...

Do you mean the vertical speed will grow in case 1 ? It is like you put horizontal spring at the bottom of the conical funnel that expands from bottom to the top and the spring extends sideways and moves up inside the funnel because it pushes on the sloped walls ? :-)

Then, the work was done, energy was lost, where is that energy now ? At some stage it was supposed to be the mechanical energy of an expanding parcel. What happened to it next?

No move - no work. So all work is done in vertical direction in case 2 In case 1 - all additional volume is at the sides, perhaps all work is done in horizontal direction.

What about extra speed of parcels in Situation 2 ?

Yes, it is what I mean. Do we have any extra mechanical energy in Situation 2 ? If yes - where did it come from ?

The air parcel expands as it rises and this expansion, or work, causes the temperature of the air parcel to decrease. Imagine that parcels of _dry air_ go up inside the pipe that goes vertically from 0 to 5000 meters. Suppose that they go up because they are slightly warmer that the air...

Hi, I need to find some good article or book related to the modeling of this process: the parcel of air goes up from the surface to the top of troposphere ( to 12000 m ), we know the conditions at the bottom such as temperature, pressure and humidity, we assume that the parcel is isolated...

You see what they write: --------- 4 Wind load calculations For most complete and part structures, and individual members used in crane structures, the wind load, F, in kiloNewtons, is calculated from the formula F = A * p * Cf A is the effective frontal area of the part under...

Thank you very much, I will try to use it but they consider "force in the direction of the wind", I need more something like full force.

How to calculate the force of wind pressure, for example for the surface tilted at 45 degrees? I need to find some serious work related to the wind pressure force calculated for different 3D shapes affected by wind from different angles. Can somebody recommend me the good names, keywords...