CFD simulation using OpenFoam software for the case of Flow Over Flat plate and generating Velocity and Temperature Profiles in comparison with Blasius DataFull description
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This paper shows a one dimensional limited volume model of an unglazed photovoltaic warm PVT sun oriented gatherer. The unit comprises of an ordinary sun based photovoltaic PV gatherer combined with an appropriate warmth exchanger. Specifically, the
Fulid ( Discussion )
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DISCUSSION
The main idea of this experiment was to compare two ways of finding the velocity profile. From the graph that we plotted we see that its exactly a same !etween smooth and ro"gh s"rface flat plate d"e to the errors occ"rs d"ring experiments !"t from the theory those smooth and ro"gh s"rface flat plate graph at same distance from edge x are s"pposed to !e different. There are two types of flow in fl"id that !een showed in this experiment laminar and t"r!"lent flow. The differences !etween laminar and t"r!"lence flow of fl"id on the flat s"rface can !e seen on the graph that have !een plotted. #reater val"e of $ was o!tained when the plane is ro"gh while the $ val"e !ecomes lesser when the distance from the edge of the plate is f"rther. f"rther.
Comparison for graph for y versus (u/U) at 0.05 m
%ased on the graph for smooth plate and ro"gh plate the intersection of !oth s"rface at &'.().'*. %y referring the val"e for smooth plate the maxim"m val"e at +.,- for ).' "U. From this graph we can see that the constant val"e for smooth plate at ).' "U from '.( "ntil +.,-. This val"e can !e accepted !eca"se the val"e has repeat parameters at seven times with contin"o"sly. In the smooth plate we can see the pattern of res"lt contin"o"sly increasing. /nother /nother graph is ro"gh plate. %ased on this graph we can analysis the maxim"m val"e is ) "U at +.,-. Other than that the minim"m val"e is '.0 "U at point ' of y. Then from this graph we also can 1now the val"e of ro"gh s"rface smaller than smooth s"rface weat weathe herr maxi maxim" m"m m or mini minim m"m val" val"e. e. This This val" val"ee can can !e acce accept pted ed !eca !eca"s "see the the val" val"ee has has repeat parameters at seven time contin"o"sly. In the ro"gh plate we can see the pattern of res"lt also contin"o"sly increasing.
Comparison for graph for y versus (u/U) at 0.2 m
%ased on the graph for smooth plate and ro"gh plate the intersection of !oth s"rface at &+.''.2*. %y referring the val"e for smooth plate the maxim"m val"e at ,.0 for ).' "U. From this graph we can see that the constant val"e for smooth plate at ).' "U from +.' "ntil 3.'. For the minim"m val"e is'.04- "U at ' point of y. This val"e can !e accepted !eca"se the val"e has repeat parameters at seven times with contin"o"sly. contin"o"sly. In the smooth plate we can see the pattern of res"lt contin"o"sly increasing. /nother /nother graph is ro"gh plate. %ased on this graph we can analysis the maxim"m val"e is ).' "U at 3.'. Other than that the minim"m val"e is '.04-"U at point ' of y. Then from this graph we also can 1now the val"e of
ro"gh s"rface smaller than smooth s"rface for minim"m and !igger val"e for maxim"m. This val"e can !e accepted !eca"se the val"e has repeat parameters at seven time contin"o"sly. In the ro"gh plate we can see the pattern of res"lt also contin"o"sly increasing.
%ased on comparison a!ove we 1now that when the distance x is increase the val"e of velocity stream will also increase. %"t in this experiment the val"e is slightly same !eca"se some error occ"rs in this experiment. The val"e of smooth s"rface is less that val"e on ro"gh s"rface d"e to the theory of effect of ro"ghness s"rface to the velocity profile.
Other than that the ro"ghness of the s"rfaces was effected the val"es of the press"res. The appearing of laminar and t"r!"lent are depending on the smooth or ro"gh of the flat plate if the s"rface is smooth the transition of laminar to !e t"r!"lent will delay while when the s"rface is ro"gh the transition of laminar to !ecome t"r!"lent will !e 5"ic1 as there are small dist"r!ance in the velocity profiles that ma1e the flow easily pass thro"gh it. The differences of the velocity profiles showed on the graph plotted and the free stream velocity calc"lated was !ased on the s moothness and ro"ghness of the s"rface.
&a* !o"ndary layer growth on a smooth s"rface
&!* !o"ndary layer growth on a ro"gh s"rface
There are a few errors occ"rred in this experiment s"ch as parallax error d"ring ta1ing data from the experiment. Other than that the error occ"rred when we calc"lated the U at -'mmand +''mm. Then at the same time we also meas"re the pitot t"!e in the same level. Unfort"nately o"r instr"ment is not capa!le on meas"ring the U at -'mm is !eca"se the t"!e that meas"re at -'mm does not fit at the hole. So all the calc"lation involve U will !e ta1en at+''mm only.
CONC6USION The !o"ndary layer velocities for the flat plate with smooth and ro"gh s"rface have !een o!tained where the data can !e seen from the ta!le. The smooth s"rface will carry initially ma1e a laminar flow and !ecome t"r!"lent t the end. 7hile ro"gh s"rface will ma1e t"r!"lent flow at the !eginning of the flow. The velocity profiles of the flat plate have !een o!tained thro"gh data read and the graphs have !een plotted. The ro"ghness of the flat plate gives the variety of the velocity profile. It can !e concl"ded that the s"rface ro"ghness of the flat plate infl"ences the velocity profiles where the smooth s"rface will delay the transition while the ro"gh s"rface will ma1e the transition !ecome faster. It will ma1e all the o!8ective of this experiment is completely o!tained.
