|
|
Water column separation under hydraulic turbine runner during unsteady operating regimes.
Vašek, Lubomír ; Rudolf, Pavel (referee) ; Habán, Vladimír (advisor)
In this diploma thesis called Water column separation under the hydraulic turbine runner during unsteady operating regimes are solved the pressure pulsations of the reverse water hamer. In the thesis is deduced a mathematical relationship of elaboration the numerice model which is based on equations of continuity and equations of forces equilibrium. Numerical model is created in MS Excel uses for computation the numerical method Lax-Wendrof that allows consideration of variable sound speed as function of static pressure and allows variable lenght step in computation domain. Reverse water hammer is in the thesis solved with consideration of rotating flow behind shut-off valve, where we expect forming of vortex rope. This situation can be applied on the closing water turbine which has vertex rope under turbine runner. Specifically for this thesis was carried out the experiment of the reverse water hammer. Constants going into numerical solution are optimalized with using experiment and pressure pulsation are compared between numerical solution and experiment.
|
|
|
Numerical model of air valve
Luňák, Pavel ; Štigler, Jaroslav (referee) ; Himr, Daniel (advisor)
This diploma thesis deals the formation of water hammer in pipes and the suppress the nega-tive effects especially for the use of protective devices (surge tank, air chamber, air valve and other). The special attention is paid to the use of the air valve, for which it was developed mathematical model. The solution is based on the use of numerical methods Lax-Wendroff with boundary conditions for the air valve.The numerical results are confronted with the ex-periment in conclusion.
|
|
|
Numerical model of air valve
Luňák, Pavel ; Štigler, Jaroslav (referee) ; Himr, Daniel (advisor)
This diploma thesis deals the formation of water hammer in pipes and the suppress the nega-tive effects especially for the use of protective devices (surge tank, air chamber, air valve and other). The special attention is paid to the use of the air valve, for which it was developed mathematical model. The solution is based on the use of numerical methods Lax-Wendroff with boundary conditions for the air valve.The numerical results are confronted with the ex-periment in conclusion.
|
|
|
Solution of Non-Linear Hydraulic Networks
Himr, Daniel ; Kozubková, Milada (referee) ; Šklíba, Jan (referee) ; Abaid, Emhemmed (referee) ; Pochylý, František (advisor)
Thesis deals about solution of non-steady flow in hydraulic systems, which have one dominant component of velocity. Such systems can be arbitrarily structured and they are not limited by number of elements. Computation is based on Lax-Wendroff method and enables considering of variable sound peed as function of static pressure and properties of pipe material. It means, that hydraulic system can be very various. Numerical method is described in detail and description is also focused on sensitivity of method for time step and length step. It can be very imported for evaluation of numerical viscosity, which is compared with second viscosity of fluid. Hammer is working title of software, which was developed on the basis of written numerical procedures. This software enables fast computation of flow in pipe-line systems.
|
|
|
Water column separation under hydraulic turbine runner during unsteady operating regimes.
Vašek, Lubomír ; Rudolf, Pavel (referee) ; Habán, Vladimír (advisor)
In this diploma thesis called Water column separation under the hydraulic turbine runner during unsteady operating regimes are solved the pressure pulsations of the reverse water hamer. In the thesis is deduced a mathematical relationship of elaboration the numerice model which is based on equations of continuity and equations of forces equilibrium. Numerical model is created in MS Excel uses for computation the numerical method Lax-Wendrof that allows consideration of variable sound speed as function of static pressure and allows variable lenght step in computation domain. Reverse water hammer is in the thesis solved with consideration of rotating flow behind shut-off valve, where we expect forming of vortex rope. This situation can be applied on the closing water turbine which has vertex rope under turbine runner. Specifically for this thesis was carried out the experiment of the reverse water hammer. Constants going into numerical solution are optimalized with using experiment and pressure pulsation are compared between numerical solution and experiment.
|
guest ::
