Page 127 - Special Issue Modern Trends in Scientific Research and Development, Case of Asia

International Journal of Trend in Scientific Research and Development (IJTSRD)
Special Issue on Modern Trends in Scientific Research and Development, Case of Asia
Available Online: www. ijtsrd. com e-ISSN: 2456 – 6470

A Hydraulic Impact Theory and

Calculation with Breaking Flow Continuity

1
2
Ulugmurad Jonkobilov Umbarovich , Sobir Jonkobilov Ulugmuradovich ,
4
Ulug’bek Rajabov Mamashoevich , Shuhrat Khoshiyev Panjiyevich
3
3
1 Doctor of Technical Sciences, Doctoral Student, Senior Teacher, Assistant,
2
4
1,3 Karshi Engineering and Economic Institute, Karshi, Uzbekistan
2 Tashkent Irrigation and Agricultural Mechanization Engineers Institute, Tashkent, Uzbekistan
4 Karshi Branch Tashkent Irrigation and Agricultural Mechanization Engineers Institute, Karshi, Uzbekistan

ABSTRACT pressure in the flow rupture event continuity, taking into
The article presents the theoretical studies results of account the pressure loss due to friction in a long pressure
hydraulic shock with flow continuity rupture in the pipeline.
pressure the pumping station pipeline. Calculated
dependencies are obtained for calculating the shock 2. CALCULATION METHOD
pressure magnitude and the first period duration of Water is supplied by a pump at a speed V0 to the pressure
reduced pressure, taking into account the hydraulic basin. A non-return valve is installed at the beginning of the
resistance along the pipeline length in the discontinuity discharge pipeline. When the check valve is instantly closed,
event in the flow. The calculation results are compared with the water stops and the water pressure instantly decreases
the Professor D.N. Smirnov’s experiments results. by the aV 0 value, where g is the gravity acceleration, a is the

Comparative calculations using the proposed method with g
D.N. Smirnov experimental data gives a satisfactory propagation velocity of the shock wave.
agreement and confirms the proposed method reliability.

With the above hydraulic process, the following condition is
KEYWORDS: water hammer, pressure pipeline, water hammer met:
pressure, flow continuity rupture, reduced pressure duration, aV 0
check valve, vacuum, friction head losses > H + H вак. макс. + H тр (1)
0
g
1. INTRODUCTION
Currently, in the Republic of Uzbekistan, 1,693 pieces of where Hвак. max. Is the value of the vacuum in the source of the
irrigation pumping stations are used to irrigate more than hydraulic shock;
2.3 million land hectares. Ensuring the normal operation
safety and reliability of the pumping stations used is in Hтр. is friction head loss up to the considered point of the
current importance. A dangerous process during normal pressure pipeline cross-sections;
operation of pumping stations pressure pipelines, as you
know, are hydraulic shocks, accompanied by the breaks H0 is geodetic head.
formation in the flow continuity in the injection water
supply. The water hammer study, taking into account the When condition (1) is met, the flow continuity rupture
continuous flow rupture in pressure systems, has not yet occurs at the check valve, and water continues to move at a
been fully studied [1,2,3,4]. Any scientific information on the certain residual velocity through the pressure pipeline.
water hammer study is relevant. This work is devoted to this
issue. The Allievi chain equations connecting the heads Hi and Hi-1
- and the velocities Vi and Vi-1 - in the section of the pipeline
An experimental water hammer study taking into account
at the gate in the i-th and (i-1) - th phases have the form
the flow discontinuity is given in [3,4,5,6,7]. These works
[9,10,11]:
[3,4,5,6,7] did not take into account the reduced pressure
duration in the first impact phase, no dependences are given H +H - 2H = a ( -VV ) , (2)
i - 1 i 0 i i - 1
to determine the phases number of the water hammer. This g
data is very important for the impact parameters analysis. for the first phase Hi = - Hвак. max.

In [8], theoretical studies have been carried out, which are
related to the discontinuity formation in the water flow in a Then from (2) we obtain:
pipeline and by determining the maximum pressure H - H - 2H = a (V - V ) ,
magnitude during hydraulic shock in different sections along 0 вак .макс . 0 g 1 0
its length. However, in [8], short pipelines are provided, in
which the pressure losses due to friction along the length can from where
be ignored. g
V1 = V0 – V*,where V = (H + H вак. макс ) , V1 – represents
0
*
The work purpose is to determine the maximum pressure a
during a hydraulic shock in the first period of reduced the residual speed with which the water mass torn off near
ID: IJTSRD37970 | Special Issue on Modern Trends in Scientific Research and Development, Case of Asia Page 122