Abstract
Evaluation of surge-control facilities for hydro power development is essential in order to achieve favourable hydraulic conditions and economical sizing of pipeline systems. The functions of surge chambers are investigated in the light of three aspects, i.e., (i) water-hammer pressure wave transmission; (ii) stability behaviour of surge oscillations; and (iii) energy relationship of flow under transient state. Experiments and analytical studies were made to examine pressure wave transmission. Compared with the Johnson differential chamber, both the change in its orifice position and local expansion of its riser play significant roles in reduction of the transmission. In most cases, the former has a more pronounced effect than the latter. Different turbine governing modes result in different degrees of stability. A combination of constant power and constant gate opening is applied to a surge chamber shared by two or more turbines. Compared with the case of constant power only, the common chamber requires a smaller cross-section for the stabilization of small-amplitude surges. The Liapunov stability theory provides a direct and qualitative procedure for judging the stability of non-linear surge oscillations. The Liapunov function represents the total specific energy of the system with surge tank. The conditions of existence of the function lead
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Citation Formats
Xiaoliang, Yang.
Pipeline transients and surge-tank stability.
Sweden: N. p.,
1993.
Web.
Xiaoliang, Yang.
Pipeline transients and surge-tank stability.
Sweden.
Xiaoliang, Yang.
1993.
"Pipeline transients and surge-tank stability."
Sweden.
@misc{etde_10117191,
title = {Pipeline transients and surge-tank stability}
author = {Xiaoliang, Yang}
abstractNote = {Evaluation of surge-control facilities for hydro power development is essential in order to achieve favourable hydraulic conditions and economical sizing of pipeline systems. The functions of surge chambers are investigated in the light of three aspects, i.e., (i) water-hammer pressure wave transmission; (ii) stability behaviour of surge oscillations; and (iii) energy relationship of flow under transient state. Experiments and analytical studies were made to examine pressure wave transmission. Compared with the Johnson differential chamber, both the change in its orifice position and local expansion of its riser play significant roles in reduction of the transmission. In most cases, the former has a more pronounced effect than the latter. Different turbine governing modes result in different degrees of stability. A combination of constant power and constant gate opening is applied to a surge chamber shared by two or more turbines. Compared with the case of constant power only, the common chamber requires a smaller cross-section for the stabilization of small-amplitude surges. The Liapunov stability theory provides a direct and qualitative procedure for judging the stability of non-linear surge oscillations. The Liapunov function represents the total specific energy of the system with surge tank. The conditions of existence of the function lead to criteria of asymptotic stability for the system. Mathematical manipulation of the differential equations governing water hammer provides an energy equation for the system with surge chamber. The equation states the relationship between the total energy, the convective energy, the work done on the system and the frictional energy dissipation. The energy approach sheds light upon the behaviour of transient flow in pipelines. 99 refs, 13 figs}
place = {Sweden}
year = {1993}
month = {Dec}
}
title = {Pipeline transients and surge-tank stability}
author = {Xiaoliang, Yang}
abstractNote = {Evaluation of surge-control facilities for hydro power development is essential in order to achieve favourable hydraulic conditions and economical sizing of pipeline systems. The functions of surge chambers are investigated in the light of three aspects, i.e., (i) water-hammer pressure wave transmission; (ii) stability behaviour of surge oscillations; and (iii) energy relationship of flow under transient state. Experiments and analytical studies were made to examine pressure wave transmission. Compared with the Johnson differential chamber, both the change in its orifice position and local expansion of its riser play significant roles in reduction of the transmission. In most cases, the former has a more pronounced effect than the latter. Different turbine governing modes result in different degrees of stability. A combination of constant power and constant gate opening is applied to a surge chamber shared by two or more turbines. Compared with the case of constant power only, the common chamber requires a smaller cross-section for the stabilization of small-amplitude surges. The Liapunov stability theory provides a direct and qualitative procedure for judging the stability of non-linear surge oscillations. The Liapunov function represents the total specific energy of the system with surge tank. The conditions of existence of the function lead to criteria of asymptotic stability for the system. Mathematical manipulation of the differential equations governing water hammer provides an energy equation for the system with surge chamber. The equation states the relationship between the total energy, the convective energy, the work done on the system and the frictional energy dissipation. The energy approach sheds light upon the behaviour of transient flow in pipelines. 99 refs, 13 figs}
place = {Sweden}
year = {1993}
month = {Dec}
}