TY - GEN
T1 - Numerical analysis of influence of pipe length on cavitation surge
AU - Iga, Yuka
AU - Nishitanaka, Hayato
AU - Yoshiki, Yoshida
PY - 2011/12/1
Y1 - 2011/12/1
N2 - Generally, in boundary condition of numerical simulation of internal flow, flow velocity is fixed in the inlet boundary and static pressure is fixed in the outlet boundary or the inverse condition, which is supposed that upstream and downstream pipes and the uniform flows inside the pipes extend infinitely from the boundaries. Therefore, a numerical simulation of influence of pipe length of fluid machinery cannot be realized by changing a boundary position of the computational region. In the present study, a boundary condition which is taking into account a pipe length is used to numerical simulation of unsteady cavitation in three-blade cyclic cascade, where generalized unsteady Bernoulli equation is adapted to one dimensional region from a upstream tank to the inlet boundary. In the study, cavitation surge frequencies reproduced in the present study are compared with empirical and theoretical characteristics of cavitation surge frequencies. Then, it shows good agreement with empirical frequency of cavitation surge although it does not take into account of the system such as pipe length. On the other hand, the theoretical frequency, which takes into account of the system, predicts a value which is less than half of the present numerical result.
AB - Generally, in boundary condition of numerical simulation of internal flow, flow velocity is fixed in the inlet boundary and static pressure is fixed in the outlet boundary or the inverse condition, which is supposed that upstream and downstream pipes and the uniform flows inside the pipes extend infinitely from the boundaries. Therefore, a numerical simulation of influence of pipe length of fluid machinery cannot be realized by changing a boundary position of the computational region. In the present study, a boundary condition which is taking into account a pipe length is used to numerical simulation of unsteady cavitation in three-blade cyclic cascade, where generalized unsteady Bernoulli equation is adapted to one dimensional region from a upstream tank to the inlet boundary. In the study, cavitation surge frequencies reproduced in the present study are compared with empirical and theoretical characteristics of cavitation surge frequencies. Then, it shows good agreement with empirical frequency of cavitation surge although it does not take into account of the system such as pipe length. On the other hand, the theoretical frequency, which takes into account of the system, predicts a value which is less than half of the present numerical result.
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U2 - 10.1115/AJK2011-06066
DO - 10.1115/AJK2011-06066
M3 - Conference contribution
AN - SCOPUS:84881454722
SN - 9780791844403
T3 - ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011
SP - 351
EP - 357
BT - ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011
T2 - ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011
Y2 - 24 July 2011 through 29 July 2011
ER -