1. Tarek ElGammal Tomoki Sakamoto Prof. Ryoichi Amano
Exploring the Cavitation Sensitivity in New Designs of Micro-Kaplan Hydro-Turbines
Tarek ElGammal Tomoki Sakamoto Prof. Ryoichi Amano
Mechanical Engineering, CEAS
2018

2. Introduction Hydroelectricity started in WI during the 19th century.
Most efficient electricity-generation system (90-95%).
Accounts for 16.4% of the World’s electric power capacity, but leads the renewable energy systems by 71%.
Paper mill in Appleton
Statistics:

3. Introduction
Most of the generated hydroelectricity is based on small-to-large scale turbines ( MW) with storage in dams.
Lately, DOE stated that 200,000 GWh/year is a potential in rivers.
Run-of-river and pumped storage technologies are paid attention nowadays through the micro Kaplan hydro-turbines (5-100 kW).
Voith reached 100 MW turbine
Kaplan is efficient at low-head stream of water (i.e. run-of-river and small pumped storage)

4. Technology Challenges
Multiple designs variables for an efficient system
Cavitation: bubble implosion (1 GPa) and micro-jets (100 m/s). Dramatic low performance and turbine damage.
Diseconomies of small scale

5. Objectives
Designing efficient regular micro-turbines (RT) to suit the new expansive market.
Propose and build novel hydroelectric systems (e.g. Rim-Drive or RDT).
Investigating the cavitation sensitivity in the new models and submitting ideas to control it.

6. Results The two turbines follow the same efficiency trend.
The optimum run occurs at N= 3000 rpm and Pout,gage= -24 kPa (the closest negative equivalent to Pin, gage= 27 kPa).

7. Results
TLV is missed in RDT because of the rim integration
RDT cavitation avoids the adjacent area to the blade tip
RDT cavitation skips the intersection locus of blades/rim leading to a reduction in the cavitation area.
Cavitation startup coverage on the RT blades suction side is nearly 200% more than RDT.
Hub cavitation has a faster tendency in RDT than RT.
Diseconomies of small scale

8. Results
3000 rpm
Diseconomies of small scale
4000 rpm

9. Results
The RDT efficiency bests that of RT at the same operating conditions by 15.1% (non-cavitating flow) and 16.5% (cavitating).
Diseconomies of small scale

10. Conclusions
RDT is more efficient by ~15% because of saving the energy losses at power. transmission.
RDT design induces less cavitation at the beginning.
Despite the efficiency drop at extreme cavitation conditions, RDT maintains higher levels of performance than RT.