Page 130 - Special Issue Modern Trends in Scientific Research and Development, Case of Asia
P. 130

International Journal of Trend in Scientific Research and Development (IJTSRD) @ www. ijtsrd. com eISSN: 2456-6470

        1. For experience II we have data:
                                                                              2
        V0 = 1,16 m/sec; Н0 = 40,0 m; Нтр = 55,0 м; Нвак.max. = 7,0 m; а   V1, 5тр = 0, 66·0,08  = 0, 00
        = 922 m/sec; tф = 2,50 sec; d = 50 mm.
                                                               V2 = V1, 5 - V* - V1, 5тр = 0, 08 – 0, 32 – 0, 00 = - 0, 24 m/sec;
        According to the initial data of the second experiment, we
                                                                            2
        calculate:                                             V2тр = 0, 66·0,24  = 0, 04 m/sec;
         аV 0         1 l   L                                  V2, 5 = V2 - V* + V2тр = - 0,247 – 0,32 + 0,04 = 0,52 m/sec;
              = 109,0 м;   ×  =  , 0  44  sec/м; V* = 0,50 m/sec; Vтр
          g           2 d   a                                                2
                                                               V2, 5тр = 0,66·0,52  = 0,18 m/sec;
                  2
        = 0,44·0,50  = 0,11 m/sec;
                                                               V3 = V2, 5 - V* + V2,5тр = - 0,52 – 0,32 + 0,18 = - 0,66 m/sec.
                 *
        V  = V* - V 1тр = 0,50 – 0,11 = 39 m/sec; V1 = V0 – V* = 1,16 –
         *
        0,50 = 0,66 m/sec;                                     Taking into account ∑ V1 = 0, we can write:
                                                               Q = 2(0, 78 + 0, 00 – 0, 04 – 0, 18) = 2·0, 56 = 1, 12 m/sec;
                      2
        V1тр = 0,44·0,66  = 0,19 m/sec; V1,5 = V1 - V* - V1тр = 0,66 –
        0,50 – 0,19 = 0,03 m/sec;                              R = 2V1тр + 3V1, 5тр - 4V2тр - 5V2, 5тр = 1, 56 – 0, 16 – 0, 90 = 0,
                                                               50 m/sec;
        V1,5тр = 0,44·0,03  = 0,00; V2 = V1,5 - V* + V1,5тр = 0,03 – 0,50 +
                      2
        0,00 = 0,53 m/sec;                                     V0 – R = 1, 50 – 0, 50 = 1, 00 m/sec;

        V2тр = 0,44·0,53  = 0,12 m/sec; V2,5 = V2 – V* + V2тр = - 0,53 –   2V0 + V* - Q = 3, 00 + 0, 32 – 1, 12 = 2, 20 m/sec; 2,20  = 4, 84;
                     2
                                                                                                          2
        0,50 + 0,12 = 0,91 m/sec.
                                                               4V* = 4·0, 32 = 1, 28 m/sec; 8V*(V0 – R) = 2, 56·1, 00 = 2, 56
        Taking into account the condition (Vn) < V1 and taking into   м /sec ;
                                                                    2
                                                                2
        account the friction forces, to determine n using formula
        (18), we will first calculate:                                        2
                                                                 (2V 0  +V *  -Q  ) 8- V *  V (-R  = ) 28,2  =  , 1  51 m/sec
                                                                                      0
        Q = 2(V1тр - V1, 5тр) = 2·0, 19 = 0, 38 m/sec;
                                                                    , 2  20 +  , 1 51  , 3 71
        R = 2 V1тр - 3 V1, 5тр = 2·0, 19 = 0, 38 m/sec;        n  =           =         =  , 2  90   =n  , 2  90;
                                                                       , 1 28       , 1 28
        2V0 + V* - Q = 2, 32 + 0, 50 – 0, 38 = 2, 44 m/sec;

                                    2
                         2
                                        2
        22 V0 + V* - Q = 2,44  = 5, 8536 м /sec ;              tv = n·tф = 2,90·4,80 = 13,92 sec; по опыту tv = 11,10 sec;

        4V* = 4·0, 50 = 2, 00 m/sec;
                                                               V2,90  =  V2,5  –  0,40/0,50(V3  -  V2,5)  =  -  0,52  –  0,11  =  -  0,63
                                                    2
                                                        2
        8V*(V0 – R) = 4, 00(1, 16 – 0, 38) = 4·0, 78 = 3, 12 m /sec ;   m/sec;

                       2
          (2V 0  +V *  -Q  ) 8- V *  V (-R  = ) 733,2  =  , 1  65 m/sec.   ΔН2 = 55, 56·0, 88 = 48, 9 м; по опыту ΔН2 = 49, 0 м.
                               0


                                                               4.  CONCLUSIONS
        Based on the above calculated calculations, we determine the
                                                               Taking into account the above, in conclusion, we can draw
        n value:
                                                               conclusions.
              , 2  44+  , 1 65  , 4  09                        1.  The  dependence  is  obtained  for  calculating  the
         n  =          =      =  , 2  04 , n = 2, 04;             maximum pressure during a hydraulic shock in the first
                 , 2  00  , 2  00
                                                                  period of reduced pressure in the event of a rupture of
                                                                  the  continuity  of  the  flow,  taking  into  account  the
        tv = n·tф = 2,04·2,50 = 5,10 sec; from experience tv = 5,10 sec;
                                                                  pressure loss due to friction in a long pressure pipeline.
        V2,04 = - 0,56 m/sec;                                  2.  The ratio for determining the number of phases during
                                                                  the impact process is obtained.
        ΔН2 = 93, 98(0, 39 + 0, 56) = 89, 28 м;
                                                               3.  The obtained ratios are very important for the analysis
        from experience ΔН2 = 86,0 м.                             of technical parameters of water hammer.

        2. According to V experience, we have data:            References
        V0 = 1, 50 m/sec; Н0 = 10,0 м; Нтр = 82,5 м; Нвак.max. = 8, 0 м;   [1]   Rongsheng  Zhu,  Qiang  Fu,  Yong  Liu,  Bo  He,  Xiuli
        а = 545 m/sec; tф = 4, 80 sec; d = 50 mm.                   Wang.  The  research  and  test  of  the  cavitation
                                                                    performance  of  first  stage  impeller  of  centrifugal
        Next, we calculate:                                         charging  pump  in  nuclear  power  stations.  Nuclear
                       1 l L               a                        Engineering and Design. China. 2016. 74-84.
        V* = 0, 32 m/sec;     =  , 0  66 m/sec;   = 55 , 56 sec;
                       2 d  a              g                   [2]   Bojan  Ivljanin,  Vladimir  D.  Stevanovic,  Aleksandar
                     2
                                    *
                                           *
        Vтр = 0, 66·0,32  = 0, 07 m/sec; V  = V* - V тр = 0, 25 m/sec;   Gajic.  Water  hammer  with  non-equilibrium  gas
                                                                    release. International Journal of Pressure Vessels and

                                                                    Piping. Serbia. 2018. 229–240.
        V1 = V0 - V* = 1, 50 – 0, 32 = 1, 18 m/sec;
                                                               [3]   Arifjonov A. M., Djhonkobilov U. U. Water hammer in
        V1тр = 0, 66·1,18  = 0, 78 m/sec;                           homogeneous  and  gas-liquid  pressure  pipelines.
                      2
                                                                    Monograph. Toshkent, TIIIMSKh, 2018.- 142 p.
        V1,5 = V1 - V* - V1тр = 1,18 – 0,32 – 0,78 = 0,08 m/sec;
        ID: IJTSRD37970 | Special Issue on Modern Trends in Scientific Research and Development, Case of Asia   Page 125
   125   126   127   128   129   130   131   132   133   134   135