For an incompressible, steady flow state on an L-length planar plate with velocity profile u = ay + b

n a) Find the velocity profile by writing the boundary conditions.

n b) Calculate the boundary layer thickness (x).

n c) Calculate the coefficient of friction Cf(x)n

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Activated Sludge (Pages 501-502, 510 Davis & Cornwell 5th edition), 3. (40 points) Study the section "Sludge Problems" on textbook, Page 510, and the additional materials from the Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and Other Solids Separation Problems. edited by David Jenkins, Michael G. Richard, Glen T. Daigger. All the reading materials are copied below. Discuss the common causes of sludge bulking and how to control the sludge bulking. Sludge problems. A bulking sludge is one that has poor settling characteristics and poor compactability. There are two principal types of sludge bulking. The first is caused by the growth of filamentous organisms, and the second is caused by water trapped in the bacterial floc, thus reducing the density of the agglomerate and resulting in poor settling. Filamentous bacteria have been blamed for much of the bulking problem in activated sludge. Although filamentous organisms are effective in removing organic matter, they have poor floc-forming and settling characteristics. Bulking may also be caused by a number of other factors, including long, slow-moving collection-system transport; low available ammonia nitrogen when the organic load is high; low pH, which could favor acid-favoring fungi; and the lack of macronutrients, which stimu- lates predomination of the filamentous actinomycetes over the normal floc-forming bacteria. The lack of nitrogen also favors slime-producing bacteria, which have a low specific gravity, even though they are not filamentous. The multicellular fungi cannot compete with the bacteria normally, but can compete under specific environmental conditions, such as low pH, low nitrogen, low oxygen, and high carbohydrates. As the pH decreases below 6.0, the fungi are less affected than the bacteria and tend to predominate. As the nitrogen concentrations drop below a BODs: N ratio of 20:1, the fungi, which have a lower protein level than the bacteria, are able to produce normal protoplasm, while the bacteria produce nitrogen-deficient protoplasm. A sludge that floats to the surface after apparently good settling is called a rising sludge. Rising sludge results from denitrification, that is, reduction of nitrates and nitrites to nitrogen gas in the sludge blanket (layer). Much of this gas remains trapped in the sludge blanket, causing globs of sludge to rise to the surface and float over the weirs into the receiving stream. Rising-sludge problems can be overcome by increasing the rate of return sludge flow (Q.), by increasing the speed of the sludge-collecting mechanism, by decreasing the mean cell residence time, and, if possible, by decreasing the flow from the aeration tank to the offending tank. 4 Control of Activated Sludge Bulking and Other Settling Problems The y demands bill penis experientations and the boy Frk 18-24 MA Me activit ben The ligh facts can be manipulados atid proces pece and city the Cred fand e the the identi done for ioloeution is tiv sueel al' s lawlilpe of flor qyeaiபு: uditin al valever danced lemine the L INTRODUCTION side Since the left kineral 1964 much has been mod about f et action de ling chance and how the long beunden the case can be di lg stichity is conted by the phyical chemical vide and mar de te id peaing Te past toe donabs fare as iifa anuptia Froatpiரி understanding of the specific fact that com vated sale stiebliny and the measures that pl designers and open can achieve b of sale stability. This undertanding is weld in spic saesaris nad vastvar po day the le cause i natient liny lie vid by desi whing anised date voting hens in concential drid, latly te and designed as This them the activated tech and how the utiar w yens r nulla uties d face in te and by by p potens Plans with potem p ing chaps that impleng caput;chunpipanaintainonpatie hiling and other IL GENERAL APPROACH The prese exquif isms is all one of the most common activated ping pins. The presence produce a nal tat eto dul and compani por it come a dates ala nhar yen upes Other yo of sing pada bed and dealt with wing the procedures ined below es with the avthult of alticleipinaccoulpt.trait un monbd ppl epithe maint pen phlen-im plat impetits rig ppi di and opening d Revet case many of these tipe developed relatively mody, even well design pel plan can experieu poblems from anticipated operating conditions. Comepently, many the a long time indile . Alter caus at make a boat tantesta pain pablity may ipoe sely inly be a bapt is rea- contingi cavall tine MXI haumpitey tial ven. M topiclieaility is a ພາ ng Pit 1980, 73 MCCA inging the option Dante 23 capito de ஷ்ெ the cellulic ooiece ishe de The ting d bu Rapp Tit Then the w denise g MAS Min of denicah or it wa all g in odide to the ac ci il te mpoites thus case-bin/ Need caused the particle, and in p kely define apin when ever IL BAPID, NONSPECIFIC BULLING CONTROL METHODS A MAR ABP on tipatian bibip:1 ndrand how these prons me and the need on the dele verald lascmlacia the celq laler Bol iqdWaitWeiploa the Sie hling the hi and 55 to thicken fickening action al they de being psy wendy dating a Presidente ped 55 city of dy dland tilby le: ti dauntritio Review day care and ar grnalily achin diaefer uputy systrn widhills ying Wing my Since its vi ud iver in han $5 in dance the 35th leting the even the c pill payer dan of the The ability micelly riper rusete d te aciand li fs rscmil lip ade dfe ire p Ipating pro of ourive fun 2. ASS and Defin in a N Fip 4 p Vand they d RAS, SX, A RASQ7 MS) à X. Q+Q tamietdan R nati dhupaths teently detierats 1. Second Chair Opting Pipe The fact of a day 1 Seconday Clanfier ces Lation une toefsion al tiken Ca te matandford die beid and for thickning faci in implying A came one for the So untsciou thot say rumlofher bodampinsumeleifonsandண்கள் on how Naktis mit C Activated Sludge (Pages 501-502, 510 Davis & Cornwell 5th edition), 3. (40 points) Study the section "Sludge Problems" on textbook, Page 510, and the additional materials from the Manual on the Causes and Control of Activated Sludge Bulking, Foaming, and Other Solids Separation Problems. edited by David Jenkins, Michael G. Richard, Glen T. Daigger. All the reading materials are copied below. Discuss the common causes of sludge bulking and how to control the sludge bulking. Sludge problems. A bulking sludge is one that has poor settling characteristics and poor compactability. There are two principal types of sludge bulking. The first is caused by the growth of filamentous organisms, and the second is caused by water trapped in the bacterial floc, thus reducing the density of the agglomerate and resulting in poor settling. Filamentous bacteria have been blamed for much of the bulking problem in activated sludge. Although filamentous organisms are effective in removing organic matter, they have poor floc-forming and settling characteristics. Bulking may also be caused by a number of other factors, including long, slow-moving collection-system transport; low available ammonia nitrogen when the organic load is high; low pH, which could favor acid-favoring fungi; and the lack of macronutrients, which stimu- lates predomination of the filamentous actinomycetes over the normal floc-forming bacteria. The lack of nitrogen also favors slime-producing bacteria, which have a low specific gravity, even though they are not filamentous. The multicellular fungi cannot compete with the bacteria normally, but can compete under specific environmental conditions, such as low pH, low nitrogen, low oxygen, and high carbohydrates. As the pH decreases below 6.0, the fungi are less affected than the bacteria and tend to predominate. As the nitrogen concentrations drop below a BODs: N ratio of 20:1, the fungi, which have a lower protein level than the bacteria, are able to produce normal protoplasm, while the bacteria produce nitrogen-deficient protoplasm. A sludge that floats to the surface after apparently good settling is called a rising sludge. Rising sludge results from denitrification, that is, reduction of nitrates and nitrites to nitrogen gas in the sludge blanket (layer). Much of this gas remains trapped in the sludge blanket, causing globs of sludge to rise to the surface and float over the weirs into the receiving stream. Rising-sludge problems can be overcome by increasing the rate of return sludge flow (Q.), by increasing the speed of the sludge-collecting mechanism, by decreasing the mean cell residence time, and, if possible, by decreasing the flow from the aeration tank to the offending tank. 4 Control of Activated Sludge Bulking and Other Settling Problems The y demands bill penis experientations and the boy Frk 18-24 MA Me activit ben The ligh facts can be manipulados atid proces pece and city the Cred fand e the the identi done for ioloeution is tiv sueel al' s lawlilpe of flor qyeaiபு: uditin al valever danced lemine the L INTRODUCTION side Since the left kineral 1964 much has been mod about f et action de ling chance and how the long beunden the case can be di lg stichity is conted by the phyical chemical vide and mar de te id peaing Te past toe donabs fare as iifa anuptia Froatpiரி understanding of the specific fact that com vated sale stiebliny and the measures that pl designers and open can achieve b of sale stability. This undertanding is weld in spic saesaris nad vastvar po day the le cause i natient liny lie vid by desi whing anised date voting hens in concential drid, latly te and designed as This them the activated tech and how the utiar w yens r nulla uties d face in te and by by p potens Plans with potem p ing chaps that impleng caput;chunpipanaintainonpatie hiling and other IL GENERAL APPROACH The prese exquif isms is all one of the most common activated ping pins. The presence produce a nal tat eto dul and compani por it come a dates ala nhar yen upes Other yo of sing pada bed and dealt with wing the procedures ined below es with the avthult of alticleipinaccoulpt.trait un monbd ppl epithe maint pen phlen-im plat impetits rig ppi di and opening d Revet case many of these tipe developed relatively mody, even well design pel plan can experieu poblems from anticipated operating conditions. Comepently, many the a long time indile . Alter caus at make a boat tantesta pain pablity may ipoe sely inly be a bapt is rea- contingi cavall tine MXI haumpitey tial ven. M topiclieaility is a ພາ ng Pit 1980, 73 MCCA inging the option Dante 23 capito de ஷ்ெ the cellulic ooiece ishe de The ting d bu Rapp Tit Then the w denise g MAS Min of denicah or it wa all g in odide to the ac ci il te mpoites thus case-bin/ Need caused the particle, and in p kely define apin when ever IL BAPID, NONSPECIFIC BULLING CONTROL METHODS A MAR ABP on tipatian bibip:1 ndrand how these prons me and the need on the dele verald lascmlacia the celq laler Bol iqdWaitWeiploa the Sie hling the hi and 55 to thicken fickening action al they de being psy wendy dating a Presidente ped 55 city of dy dland tilby le: ti dauntritio Review day care and ar grnalily achin diaefer uputy systrn widhills ying Wing my Since its vi ud iver in han $5 in dance the 35th leting the even the c pill payer dan of the The ability micelly riper rusete d te aciand li fs rscmil lip ade dfe ire p Ipating pro of ourive fun 2. ASS and Defin in a N Fip 4 p Vand they d RAS, SX, A RASQ7 MS) à X. Q+Q tamietdan R nati dhupaths teently detierats 1. Second Chair Opting Pipe The fact of a day 1 Seconday Clanfier ces Lation une toefsion al tiken Ca te matandford die beid and for thickning faci in implying A came one for the So untsciou thot say rumlofher bodampinsumeleifonsandண்கள் on how Naktis mit C

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1 To find the velocity profile we need to write the boundary conditions The boundary conditions for ... View the full answer