3. Torque and overall forces in a rotor
Due to the symmetry of the moving channels around the axis of rotation OO′, the forces exerted by the rotor on the fluid reduce, in the general case of total injection and neglecting the effects of instationarity, to :
a resultant moment about the OO′ axis, called torque, knowledge of which is essential since its work is identified with the energy exchanged between the fluid and the rotor ;
a resultant carried by OO′ whose reaction, applied to the rotor, is called thrust. This force plays an important role in the design of turbomachinery, as special measures must be taken to counteract it and keep the rotor in a fixed position in the axial direction. These consist firstly in reducing thrust by acting on the geometric shape of the rotor (a balancing operation), and secondly in supporting the residual thrust...
The Ultimate Scientific and Technical Reference
This article is included in
Hydraulic, aerodynamic and thermal machines
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Torque and overall forces in a rotor
Work exchanged between fluid and rotor
Bibliography
Websites
Profluid :
French association for pumps, mixers, compressors and valves
Standards
AFNOR standards : https://www.boutique.afnor.org/norme/
- Centrifugal pumps with axial suction PN10 with support under pump casing – Nominal operating point, main dimensions, designation system. - NF EN 733 - août 1995
- Technical specifications for centrifugal pumps – Class II. - NF EN ISO 5199 - mai 2002
- Pompes...
Laboratories – Design offices – Schools – Research centers (non-exhaustive list)
CNAM (Conservatoire National des Arts et Métiers) Turbomachinery Chair
Appendix: Overview of unsteady effects in a turbomachine
1. Centrifugal pumps
Consider a pump impeller feeding directly into a volute casing. In order to neglect three-dimensional effects, the flow is assumed to be plane, i.e. the thickness of the flow in figure 1...
Bibliography specific to Appendix A
[a] BOULBIN (F.), KERMAREC (J.), PLUVIOSE (M.): Turbine blade forces due to partial admission, Recent advances in compressor and turbine aerothermodynamics, SFM (1992).
[b] PLUVIOSE (M.), PÉRILHON (C.), TOUSSAINT (M.): Machines à fluides, Ellipses (2002).
[c] ZACCARIA (M.), LAKSHMINARAYANA (B.): Unsteady flow field due to nozzle wake interaction with...
The Ultimate Scientific and Technical Reference
