A numerical analytic process is suggested combining direct boundary element methodwith discrete vortex method and internal flow in cross-flow fan calculated. The process considersnot only function of impeller, but als...A numerical analytic process is suggested combining direct boundary element methodwith discrete vortex method and internal flow in cross-flow fan calculated. The process considersnot only function of impeller, but also effect of volute casing. Internal flow field of cross-flow fan ispractically measured, and results compared with that from calculation. It shows that the process isexpected to be used in predicting performances of fluid machinery.展开更多
A numerical analysis method has been developed for the prediction of the flow in across-flow fan with a casing. The method has no simplifying assumptions regarding the geometryof both the impeller blades and the casin...A numerical analysis method has been developed for the prediction of the flow in across-flow fan with a casing. The method has no simplifying assumptions regarding the geometryof both the impeller blades and the casing Taking into consideration the effect of the boundarylayer on the upper wall surface of the casing, the internal flow is analyzed using both the directboundary element method and the discrete vortex method by assuming that the flow istwo-dimensional. inviscid and incomtressible. In order to satisfy Kelven's theorem, vorticity is sh-ed at the trailing edges of each impeller blade, then the discrete vortex method is used to approxi-mate the convection of the free vorticity. Results are giver for the cross-flow fan with two differ-ent configurations of the casing with an dentical impeller.展开更多
In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantit...In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the network.Accordingly,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem curve.Under some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan system.In this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters technique.To show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.展开更多
文摘A numerical analytic process is suggested combining direct boundary element methodwith discrete vortex method and internal flow in cross-flow fan calculated. The process considersnot only function of impeller, but also effect of volute casing. Internal flow field of cross-flow fan ispractically measured, and results compared with that from calculation. It shows that the process isexpected to be used in predicting performances of fluid machinery.
文摘A numerical analysis method has been developed for the prediction of the flow in across-flow fan with a casing. The method has no simplifying assumptions regarding the geometryof both the impeller blades and the casing Taking into consideration the effect of the boundarylayer on the upper wall surface of the casing, the internal flow is analyzed using both the directboundary element method and the discrete vortex method by assuming that the flow istwo-dimensional. inviscid and incomtressible. In order to satisfy Kelven's theorem, vorticity is sh-ed at the trailing edges of each impeller blade, then the discrete vortex method is used to approxi-mate the convection of the free vorticity. Results are giver for the cross-flow fan with two differ-ent configurations of the casing with an dentical impeller.
文摘In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the network.Accordingly,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem curve.Under some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan system.In this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters technique.To show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.
