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Section 13. Technical sciences
2. Fozilov G. G. Determination description of the mixture which is coming through pith and husk outlet of the corn sheller machine//per-spective of development private business of agriculture: Devoted for 20 years of independence Republic scientific-applied conference's articles collection. -Andijan: - 2011. - P. 260-262.
3. Astanakulov K. D., Fozilov G. G. and others. "Development of early harvesting technological process of the ear cereal plants and corn also creating the high effective new technical implements for crop harvesting as well redevelopment the existent implements" account of the scientific-research work. - Gulbakhor, 2010. - P. 76-77.
4. Fozilov G. determination the coefficient of the useful area of corn sheller sieve according to circle holes. Journal Agro ilm. - No. 1 (39), 2016. - P. 71-72.
5. Mathematics: collection of formulas. - Moscow, Astrel, 2013. - P. 51-56.
Shukurova Sevara Egamkulovna, Bakiev Masfarif Ruzmetovich Tashkent Institute of Irrigation and Melioration, Tashkent, Uzbekistan E-mail: sevariiik@mail.ru
Floodplain correction by varying build-up combined dikes
Abstract: In the article the relationships for determination of flow dynamic axes deflection, specific discharges in unobstructed flow section has been obtained and carrying capacity has been evaluated for varying build-up combined dike perforated section asymmetrically obstructing flow.
Keywords: dam, dam combination, deaf dam, dam-through variable construction, waterworks, tightness flow hydraulics, the degree of tightness, spreading.
In spite of the fact that the idea of combined dike construction has been known long ago [1], combined dikes has been built relatively recently in Amudarya river at Takhiatash water structure complex.
Floodplain correction project in Amudarya river at Karshi main canal water intake structure has been also executed with the use of combined dikes. They asymmetrically obstruct flow in order to direct flow into water intake point.
Operation of combined dikes with constant build-up perforated part has been discussed in works [2; 3; 4].
The main principles of varying build-up perforated spur dike construction and theoretical bases for their design has been reviewed in work [5] for the first time.
The scheme for asymmetrically obstructed flow by constant build-up combined dikes is illustrated in the picture.
Picture 1. Flow asymmetrical obstruction Specific discharge uniform plot reforms in section line I-I under dike action and in section 0-0 its shape looks like what is shown in the picture.
The discharge approaching the blank dike fully declines from the protected bank only when one part of the discharge approaching the perforated dike declines to unobstructed area of floodplain and the other part passes through perforated dike to tail-water on account of gradual decrease of build-up coefficient.
by varying build-up combined dams.
Obstruction dissymmetry provides more intense deflection of flow dynamic axes in the direction of shorter length dike.
The goal ofthe research within the scope ofthis article consists of:
- determining the dynamic axes deflection for left and right section of flow;
- determining the specifics discharges in unobstructed section. Considering the varying build-up along the length we accept
the velocity and specific discharge distribution behind beyond per-
Floodplain correction by varying build-up combined dikes
forated dike sections according to Shlixting — Abramovich relationship [6]
^ = (1
^ = (1
qoi
where Umi ,qmi — velocities and specific discharges beyond perforated dike sections; U0i, q0i — velocities and specific discharges in unobstructed flow section; q02 = q01 — for right section of flow,
l,sina>-Y
(1) (2)
= I oi - for left section of flow; n =
section; n =
Lsina-Y
ld1sinad - l!lsinai — for left section.
— for right
Lsina, - Ijina,
g 2 g г2 g
We use Varignon theorem to determine flow dynamic axes
deflection for section line I-I (with original flow condition) and
section line 0-0 (obstructed section line) and write it as follows:
- for right section of floodplain
B f B A nr , . (, . 2 Lsina, 1 T+f 1 = 0,5qJcisma4 l*stna* +7 c\
2 14
(go3 + goi ) 2
Lsia + 2go3 + I — - L sina
3 (goi + go3 )) 2
(3)
- for left section of floodplain
B (B A , . (, . 212sinag h-1 - + f2 I = qjc 2Sinag I Lsinag + 3 C 2 I +
+0,5(qo3 + qo2)bo:
, . 2q +q f B Lsina* +—m—I--Lsma.
(4)
3 (02+^03))2
From the first equation we determine right side flow dynamic axes deflection
r q.. l.sina, (, . 2, . ,
f = -gI Lsinag + -1.sina, | +
Jl q2 B 121 " 3 CI
(+q 01 ) b0
qi
B
Lsinag
2qo3
-(0,5B - ld 1sinag
- 0,25B (5)
3(<joi+q„3)
From the second equation we determine left side flow dynamic axes deflection
/2 = q- Lsinag yl2sinag + 3 Lsinag | +
(03 + ^02 ) bE
lg2sinad+ f02 + q03 (0,5B -ld2sinad) 3 ( + q„3 )
0,25B
+-
(6) ^^ B
By dividing the left and the right sides of both equations (5, 6) by B and after certain transformations we determine relative deflections of flow dynamic axes: - for right section
0,25 (7)
Xf = 2q0lnc 11 nzl +—nc 1 1 +
-(03+qoi )( - n )
ni + 2qoi+^ (0,5 -n1 )
3 (oi + go3 )
- for left section
= 2q02«2 I 2 + T nc2 1 +
-(03 + Î02 )(1 - »2 )
n + +^ (0,5 - »2 )
3 (03+qo3 )
-0,25 (8)
where
= fi/ B; Xf = f2/ B — relative deflections of right side and left side flow dynamic axes;
q>i = 1oi1 q.2; 1o2 = 1o2 / q2; q03 = 1«, I q2 — relative specific discharges at free flow section;
n1 = ld1sinad / B; n2 = ld2sinad / B — extent of flow obstruction by right and left dams;
ncj = lc 1sinad / B; nc2 = lc2sinad / B — extent of flow obstruction by perforated dike sections, right and left respectively;
n!l = ¡!lsinad /B; n2 = \2sinad /B — extent of flow obstruction by blank dike sections, right and left respectively;
It is obvious that the total deflection of flow dynamic axes is equal to:
/0 = f - /2 (9)
The research results show that the relative deficit of specific discharges in unobstructed flow section for this case can be described by linear relationship:
= (1 -n) (10)
Y_y q"2 -
where n = —^—1 — relative ordinate for point, where qx is determined. 0
Obviously for this case, the plot area for specific discharges in unobstructed section is equal to the sum of areas for its separate parts:
\qßy = j qxdy + j qßy
(11)
By executing integration in (11) with the account of(10) 0,5K (01+q«2)=°> 5boi (01+^03)+0,5b02 (03+q„2) we find the relationship between the values for specific discharges q01, q02, q03 and express q03 through the other two
_ _qm = Kq 02 + M01 (12)
where b01 = b0ll b0; b02 = b02l b0
Using (12) significantly eases the solution of the system of equations (7) and (8).
Specific discharges in unobstructed section of flow are determined from the equation of discharge conservation written for section lines I-I and 0-0
Idisinad +K Lsina +bn +1
q2B = J qxdy + J qxdy + J qxdy (13)
! sina^ lg ! sinag lg [ sinag
after executing integration with the account of (2) and (10) we obtain
q2B = 0,A5q Jc ¿ma + 0,5(q01 + q02 )h0 + 0,45q02/c 2sinad and dividing by q2B
1 = OA^n t + + q2 -n -n2) + 0A5q2n2 (14) It is clear from (14), that there are two unknowns in one equation. To solve the task we use the discharge equality condition, determined by mean specific and real discharges
b
qA = \q*dx (15)
0
taking into account (10) we determine
qm = 2q0 - q«2 (16)
substituting (16) in (14) we get
1 = -q02)(0,5 -0,05n1 -0,5n2 -0,45nz1 ) +
+^02(0,5 - 0,5ttj - 0,05n2 - 0,45nz2) (17)
and
— _ 1 - 2q0 (0,5 - 0,05n1 - 0,5n2 - 0,45nz1 ) q°2 _ 0,45n2 + 0,45n, -0,45n, -0,45n2
' 2 ' г1 ' 1 ' г 2
In order to determine the carrying capacity of the combined dike with constant build-up perforated section we use the concept of streamline, which is the ratio of the discharge passing through perforated dike section Qm to the oncoming discharge Q2
(18)
or
