chuong 6 dong chay thuc

Chng 6: Dong chay thc

Chng 6: Dong chay thc11/29/2013Chng 6 - Dng chy thc1

Nhng sai lch so vi mo hnh ly tng co the la:Dong chay tat cua lu chatS tuan hoan cua lu chatCac vung tu ong trong thiet b Trong tat ca cac loai thiet b thc hien qua trnh truyen nhiet, truyen khoi, ky thuat phan ng neu co cac hien tng tren se lam giam kha nang hoat ong (hieu suat) cua thiet b. Muc ch cua chng nay la anh gia nh lng anh hng cua cac sai so tren len o chuyen hoa.11/29/2013Chng 6 - Dng chy thc2

Nhng sai lech so vi mo hnh ly tng11/29/2013Chng 6 - Dng chy thc3

1. KHAI NIEM VE KHUAY TRON VA MO HNH3 phng phap c tnh cac sai so so vi ly tng:Xac nh s phan phoi thi gian lu thc te (thch hp cho thiet b phan ng dang ong, chay dong va phan ng bac mot).Mo hnh phan tan theo phng truc (thch hp cho thiet b phan ng co che o chay roi)Mo hnh he nhieu bnh khuay bang nhau mac noi tiep* Mot mo hnh khac la thiet b phan ng dang ong co dong hoan lu.11/29/2013Chng 6 - Dng chy thc4

Thiet b phan ng dang ong co dong hoan lu

11/29/2013Chng 6 - Dng chy thc5

2. S PHAN BO THI GIAN LU CUA LU CHAT TRONG BNH11/29/2013Chng 6 - Dng chy thc6Xt dng chy n nh, khng c phn ng v s bin i khi lng ring ca phn t lu cht qua thit b. Thi gian thu gn l mt bin s khng th nguyn c nh ngha nh sau:

vi :t - l thi gian phn t lu cht i qua thit b.

- thi gian lu trung bnh

- thi gian th tch

a) Ham phan bo thi gian lu cua lu chat trong bnh (ng cong I)

11/29/2013Chng 6 - Dng chy thc7K hiu I c dng ch o s phn b thi gian lu ca lu cht trong bnh: l phn lu cht c thi gian lu trong bnh t n +d.V tng tt c cc phn lu cht bng mt nn tng ny bng tng din tch bn di ng cong I theo .

b) ham phan bo thi gian lu trong bnh cua lu chat trong dong ra (ng cong E)

11/29/2013Chng 6 - Dng chy thc8E l o s phn b thi gian lu trong bnh ca tt c cc phn t ca dng lu cht ri khi bnh: l phn lu cht trong dng ra c thi gian lu trong bnh t n +d.

Ham phan bo thi gian lu cua lu chat trong bnh


3. CAC PHNG PHAP THC NGHIEM Cac dang tn hieu kch thch (stimulation) ap ng (response) thng s dung


ng cong F11/29/2013Chng 6 - Dng chy thc11ng cong C

Hnh 6.5. ng cong F biu din p ng ti dng ra cho tn hiu bc ti u vo

Hnh 6.6. ng cong C biu din p ng ti dng ra cho tn hiu xung ti u vo

Quan h gia cc ng cong F, C, I v E11/29/2013Chng 6 - Dng chy thc12

Gi s rng tn hiu c a vo ti thi im t = 0 th ti thi im t bt k cn bng vt cht cho bnh l:v ti thi im

4. S DUNG CAC THONG TIN PHAN PHOI THI GIAN LUHe phi tuyen khong co mo hnh dong chayHe phi tuyen vi mo hnh dong chayHe tuyen tnh vi mo hnh dong chay: Mo hnh dong chay c s dung e tien oan o chuyen hoa cho he tuyen tnh11/29/2013Chng 6 - Dng chy thc13

Ca hai mo hnh cho tn hieu ap ng giong nhau va tac ong tng t cho phan ng bac 1, nhng co tac ong khac nhau vi phan ng co toc o khong tuyen tnh theo nong o


Th du 6.1:Bang 6.1: Ket qua ap ng cua tn hieu xungThi gian t, phNong o chat ch th, g/lt0053105155204252301350


11/29/2013Chng 6 - Dng chy thc16Din tch bn di ng cong nng theo thi gianQ =

=

t, ph051015202530E(t) = , 00,030,050,050,040,020,01

nhn c E, i t thnh

ng bieu dien E theo t (trai) va theo (phai)


Th du 6.211/29/2013Chng 6 - Dng chy thc18Lp bng v v hm phn phi I cho th nghim trong v d 6.1


Hnh 6.10. V d 6.2

6. XC NH CHUYN HA TRC TIP T THC NGHIM11/29/2013Chng 6 - Dng chy thc20

Qu trnh tuyn tnh

Vi phn ng bc mt c rA=kCA v c khi lng ring khng i

Th du 6.311/29/2013Chng 6 - Dng chy thc21Bnh phn ng trong v d 6.1 c dng thc hin phn ng phn hy pha lng c phng trnh vn tc :

Tm t l tc cht khng chuyn ha trong dng ra khi bnh phn ng thc v so snh vi t l tc cht khng chuyn ha trong thit b phn ng dng ng c cng th tch. Thi gian th tch cho c hai bnh nh trong v d 6.1

Vi thit b phn ng dng ng c

Vi bnh phn ng thc

Th du 6.311/29/2013Chng 6 - Dng chy thc22

Vi bnh phn ng thc

tE(t)kt50,031,530,2154(0,2154).(0,03).5 = 0,0323100,053,070,04640,0116150,054,600,01000,0025200,046,140,00210,0004250,027,680,00050,0001300,019,210,00010

11/29/2013Chng 6 - Dng chy thc235. M HNH DNG CHY THC Dng chy trong thit b dng ng v ti u dng chy c mc khuy trn nht nh m ln ca n c lp vi v tr trong bnh khng c vng t, dng chy tt hoc vt dng trong bnh m hnh phn tn cho dng chy trong ng. S bin i cng khuy trn hoc chy ri m hnh ny nm gia hai cc: bnh ng v bnh khuy th tch ca bnh phn ng theo m hnh ny s nm gia hai gi tr c tnh cho bnh ng v bnh khuy.

Hnh 6.11. Biu din m hnh phn tn

11/29/2013Chng 6 - Dng chy thc245. M HNH DNG CHY THC Phng trnh vi phn cho khuch tn phn t theo phng x

= D* l h s khuch tn phn t, l thng s duy nht c trng cho qu trnh.

=

c gi l h s phn tn theo phng trc

Vi dng chy trong ng, khuy trn theo phng trc ch yu do gradient vn tc # khuy trn theo phng bn knh ch yu do khuch tn phn t.

c gi l s phn tn, l thng s dng o mc phn tn theo phng trc.

: phn tn khng ng k, nh vy dng chy ng.: phn tn hon ton, nh vy dng khuy trn.

Moi quan he gia D/uL va ng cong C vo th nguyen cho mc o phan tan nho (D/uL nh)11/29/2013Chng 6 - Dng chy thc25

Hnh 6.12. M hnh phn tn tin on s phn b tn hiu xung ti thi im bt k

Moi quan he gia D/uL va ng cong C vo th nguyen cho mc o phan tan nho, ph.tr (6.15)


ng cong C trong bnh kn cho cac mc o khuay tron khac nhau theo mo hnh phan tan


Ket qua thc nghiem s phan tan cua lu chat cua dong chay qua thap chem vi van toc trung bnh theo phng truc u


11/29/2013Chng 6 - Dng chy thc29Phn ng ha hc v phn tnnh hng ca s phn tn D/uL ln chuyn ha trong thit b phn ng. Xt mt thit b phn ng n nh c chiu di L qua lu cht chuyn ng vi vn tc khng i u v vt liu b khuy trn theo phng trc vi h s phn tn D, phn ng bc n Hnh 6.20. Cc bin s cho bnh kn trong xy ra phn tn v phn ng.

11/29/2013Chng 6 - Dng chy thc30Phn ng ha hc v phn tncn bng vt cht cho tc cht

+ Tiu th do phn ng + Tch t = 0

11/29/2013Chng 6 - Dng chy thc31Phn ng ha hc v phn tn

Gii hn khi l 0, ta c

Theo chuyn ha

Dng khng th nguyn

11/29/2013Chng 6 - Dng chy thc32(i) Phn ng bc mt

D/uL nh, ng cong E t n dng Gauss

=So snh t s kch thc t cng chuyn ha cho cc bnh phn ng tng t bnh ng.

; vi cng CA,ra t s nng dng ra cho cng c bnh:

; vi cng V

11/29/2013Chng 6 - Dng chy thc33(i) Phn ng bc mt

Hnh 6.21. So snh gia bnh phn ng thc v bnh ng cho phn ng bc mt.

11/29/2013Chng 6 - Dng chy thc34(ii) Phn ng bc hai

Hnh 6.22. So snh gia bnh phn ng thc v bnh ng cho phn ng bc hai

11/29/2013Chng 6 - Dng chy thc35(iii) Phn ng bc khng

S khuy trn khng nh hng ln kh nng hot ng ca bnh vi phn ng bc khng.

11/29/2013Chng 6 - Dng chy thc36M hnh bnh khuy mc ni tip

L m hnh mt thng s c s dng rng ri biu din dng chy thc. Lu cht chy qua mt lot cc bnh khuy l tng bng nhau mc ni tip;- Mt thng s ca m hnh l s bnh khuy c trong h. N bnh mc ni tip :

11/29/2013Chng 6 - Dng chy thc37M hnh bnh khuy mc ni tip

Hnh 6.24. ng cong phn b thi gian lu theo m hnh nhiu bnh khuy mc ni tip, phng trnh (6.34)

anh gia hoat ong cua bnh phan ng ong bng ng cong C:

11/29/2013Chng 6 - Dng chy thc38Mot so dang sai so cua bnh ong: (a) khong sai lech; (b) co dong chay tat va vung tu; (c) co hien tng tuan hoan; (d) lu lng o sai, the tch chat long, tn hieu khong thc s la tr; (e) hai dong chay song song trong thiet b

anh gia hoat ong cua bnh phan ng khuay tron bang ng cong C: Mot so dang sai so cua bnh khuay


Mt s phng php to dng chy gn t n dng chy ng trong thit b11/29/2013Chng 6 - Dng chy thc40

Hnh 6.31. Cc phng php ci thin dng chy t n dng ng.

chuong 6 dong chay thuc

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