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Design of Kaplan Runner
Speed Specific toalProportion 24 to8 :blades ofNumber :
to t l
Details of Blade Arrangement
Meridional plane : Conservation of Rothalpy
2 22 bladebladerel UV
An ideal incompressible turbomachine:
Suggested Model for Kaplan
2 rwerwi VV
01 0 dr rVd
V dr dp wwf
Radial Equilibrium Equation for Incompressible Fluid Machine
To define the distortion of the blade, the velocity triangles of at least six different radiuses of the blade are to be determined. The angle β of each radius gives conclusions on the distortion of the blade. The angles should be corrected for real hydraulics.
• The “Tragflügeltheorie” was developed by Ludwig Prandtl.
• According to the “Tragflügeltheorie” a lifting force is generated at the blades of the runner due to the configuration of the flow stream and the whirling stream, which occur at the blade.
• Hence, values such as the lift coefficient and the attack angel δ also play a significant role in the design of the blade.
• These coefficients can be determined via model tests. • Using these results the profile, the chord and the exact
distortion of the blade can be determined.
Characteristics of Blades
• Ideal Blade lift coefficient:
deaedraftsatmrmre blade KV
draft: Efficiency of draft tube: 0.88 to 0.91 K : Profile characteristic number: 2.6 to 3.0 hmin=2.0 – 2.5
When the lifting coefficient is known, the sufficiency of ratio l/t can be established as follows:
2.5°-- 3°Allowable values of angle of slip
The actual Lifting Coefficient
Calculation of Actual Angle of Slip
Actual Angle of Attack
Power Developed by the Runner
reriblade VVUmddP Power developed by a differential blade surface
Calculation of Control Forces
Ganga Hydro Elecrtic Scheme
• Tem Kaplan Turbine Power units along Ganga Canal.
• Ranipur, Pathri, Bahadrabad, Salawa, Chitaura, Nirganj, Mohammedpur, Sumera, Palra and Bhola.
• Capacity Range: 400 hp to 10,000hp. • Head Range: 5.3 m to 9.6 m