I see, I evaluate, I write...

Wednesday, November 07, 2007

This is good

To my Best Friend Raja...enjoy! Hidup mu kembali berseri. Jarang la lepak sama2 lagi.:D

To my Best Friend's GF Rina, terima kasih tak terhingga kerana membelikan saya 100g serbuk asam boi yg sudah lama menjadi idaman hati tatkala stress exam nih. Asam tu sedap tapi makcik yg buat asam tu kedekut sbb tak letak asam lebih, habuk je lebih..huhuhu

Btw, i am going to wrap up what have i learned/learnt? so far.

There are only two theories to know about this ENCI 341. Firstly is the theory of Inviscid/Irrotational Flow and another one is Boundary Layer Theorem. These two theories simply tell us about the a stream of fluid is behaving. Most importantly, these two theories are created on the basis of Navier-Stoke Equations and Mass Balance.

Inviscid Irrotational Flow theory is more applicable to an aerofoils in which the solutions obtained from the inviscid flow theories satisfies the observation. However when it comes to a bluff body this solution is simply rubbish. It is because the Inviscid Irrotational results do not show that drag is created at the downstream of the flow which is totally against the observation. Therefore to tackle this, Prandtl introduced a Boundary Layer Concept which simply says that "no matter how big your Re # is, the no-slip condition must apply at the region near the solid boundary". Hence by having this, there exist a thin layer near the solid boundary that is infinitely long.

The Boundary Layer Equations are derived by performing a scale analysis on the N-S equation of a steady flow passing through a flat plate. There are 2 key conclusions drawn upon the analysis which are mainly saying that "The diffusion of momentum on the X-direction is very small compared to the one in y-direction" Hence this allows the momentum diffusion in x-direction to be neglected in the N-S equation. Another one says that, because of the importance of the viscous effect, the remaining viscous terms will be of an order 1...

Despite the simplification achieved upon applying the assumptions, the BL equations are still difficult to be solved. However we could still perform a numerical method sing a similarity transform. The results from this numerical method shows that the velocity within the boundary layers are self-similar and this is known as BLASIUS SOLUTION.


Blogger sangkuriang said...

haha.. kau stil teman lepak aku lagi bro.. boleh je bahagikan masa.. thanks bro.. weh simpan skit asam tu.. terliur gak aku dengar.. haha

1:26 PM

Blogger Super_Duper_Yummy said...

Hohoho!! sweet as bro. No problem la, member punye pasal aku simpan la sikit utk ko rasa..hehehe

9:39 PM


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