Recent content by pigna

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    Potential flows and Helmholtz decomposition

    Ok l have posted two time the same images... sorry... as you can see confusion and no conclusions. Probably when i say that I ' m not sure if an integral goes or not to zero it actually goes because in different case I don't even use the hypothesis of irrotational flows. And as you can see I'm...
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    Potential flows and Helmholtz decomposition

    It is exactly what I'm not able to do. I have tried to do that or to rewrite the curl term as a gradient but I haven't reached any result... do you know some book or internet content that adress this issue in a comprehesible way?
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    Potential flows and Helmholtz decomposition

    Hi. I'm studying fluid dynamics and in particular potential flows. I know that for an irrotational flow the velocity field is a conservative field and it can be rapresented by the gradient of a scalar field v=-∇Φ. In this case the explicit form of Φ is something like a line integral between a...
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    I Winding number for a point that lies over a closed curve

    thanks for the replies... looks at the pdf in which I clarify what I'm interested in...
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    I Winding number for a point that lies over a closed curve

    The definitions of the winding number, that I have found, do not consider the case in which the point lies over the curve. Is there the winding number undefined ? I'm interested in this issue because I'm writing an algorihm for polygon offsetting that as first step creates a row offset polygon (...
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    Why does the formula for calculating fin surface area differ in different cases?

    They are Not included because those sides are Not suppose to Loss any heat. Normaly The heat losses for a fin are espressed per unit length. If you consider a finite fin on the directIon w you got to do some aproximations to use The same relations you Will use for an infinite fin. U also have to...
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    Why does the formula for calculating fin surface area differ in different cases?

    When you Say fin you Mean something that is Not finite along w director. This allow You to considerazione The problem as mono dimensional.
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    Helmotz decomposition definitions.

    I'm sorry the upload of the image have made its quality Dim. Now I'm using a Phone and is difficult for me to write code lines. I try to upload a pdf version of the pic. Forgive me for the unproper Way I'm posting. The quality should be better.
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    How to determine characteristic length?

    The biot number characteristic length is volume/(eternl surface). For convention problems the characteristic lengths are in according to the correlation u are using. Normaly They are the Most intuitive ones. I suggest you to look for the incropera textbook. U can find the pdf version easily...
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    Helmotz decomposition definitions.

    I' m studing the hodge helmotz decomposition of a flow Field, and i have Found different definitions. I'm Not sure to have assigned the rigth meaning to the terms of the decomposition. Look At The picture( i don't write here cose there are several equations).
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    Thermodynamic definition of volume

    I'm studynig thermodymamics using the textbook 'Thermodynamics foundations and applications' (Beretta and Gyftopopulos). The definition of a system according to the authors consist in the specification of : -the costituents of the system ( atoms or molecules or prottons neutrons ... in...
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