Design and Development of Duct-Diffuser Augmented Propeller Low Head Hydro Turbines

1. National University of Sciences and Technology (NUST) Fluid Structure Interactions Research Group Design and Development of Duct-Diffuser Augmented Propeller Low Head Hydro Turbines Tauseef Ahmed – ta3e09@soton.ac.uk - Faculty of Engineering and the Environment University of Southampton Supervisors – Dr Stephen Turnock , Dr Richard Wills, Dr Syed Waheed (NUST) • Introduction • On economic grounds, the criteria for design and development of Low Head Hydro (LHH) turbines are based on minimum cost per unit power instead of maximum delivered power. The drawback of this approach often results in undue design simplification, and hence possibly unfeasible predictions of the likely hydraulic power potential along with below average performance of the design models. • Governmental and global targets for reduction in carbon emissions, environmental impacts and the capability of serving the ever increasing demand of power requirements in the shortest time are driving forces for small/low head hydro power generation. • Design Criteria • The adopted methodology for maximum deliverable power criteria follow integration of meaningful geometry for generalized design instead of site specific tuning of non-hydro dynamic components. The addition of hydrodynamic flow regulating components for power augmentation and system level modification of component for extended range of application of technology are the main features of proposed criteria. CFD modelling and Analysis of proposed LHH turbine models The modern design, analysis and manufacturing techniques can contribute to investigate hydro potential as low as 1 meter head and a power output of 200 Watts CAD/CAM based automated design and analysis process for LHH applications is opted for real cost effective LHH designs. To simulate internal flow within turbine passages for accurate prediction of flow physics, 3 D Navier Stroke equations are solved using commercial software ANSYS CFX. The associated ANSYS ICEMCFD package for grid generation is used along with SolidWorks for CAD modelling. • Application of Computational fluid dynamic techniques particular to LHH turbine operational range of parameters to evaluate • Complex 3-D flow visualization • Component behaviour characterisation • Design optimization • Small-scale hydro power is the key source for further hydro development. Optimization of existing recourses for power harnessing has made application of low head hydro power a choice for water treatment plants, water and waste water networks TWh/Year Fig.7 Rotor-Stator Interface modelling Figure 1 Global Hydro resources review in terms of power production [1] Fig 9 Velocity distribution in stationary frame for modified geometry Fig.8 Stream line plot of velocity distribution through the model turbine unit • Design and development status of proposed LHH • Based on the design to manufacture approach and above mentioned criteria of maximizing energy for extended range of application two LHH configurations namely Diffuser Augmented and Duct-multilevel Diffuser Augmented turbine are proposed. • Following diagrams highlights schematic and component diagrams Objectives of the project • This research aims to support more consistent and optimised design with enhanced systems performance for low/ultra- low head hydro-electrical power generations. This project under International Strategic Participation In Research and Education (INSPIRE) initiative of British Council has the following goals • To exploit the potential of LHH for power output range 0.2Kw to 25kw • Flexible design for a range of operating conditions at system and component level • Continuous operation at full capacity for maximum duration with minimum control regulations (on grid/off grid) • To develop new design concept of low/small scale hydro power generation • Hydro dynamically efficient turbine runner • Performance data acquisition of laboratory units for optimum design of site specific units • Understand fully the design for propeller turbines using CFD modelling, and laboratory experiments Diffuser runner Fig 4 Runner and 7 degree diffuser CAD assembly Fig 2 Stator CAD model Fig 3 3D Runner CAD model Figure 5 Diffuser Augmented complete CAD model assembly Figure 6 Duct-Diffuser Augmented complete CAD model assembly Acknowledgement This research is jointly sponsored by National University of Sciences and Technology (NUST) and British Council International Strategic Partnership In Research & Education (INSPIRE) Initiative References [1] International Journal of Hydropower and Dams: World Atlas. Sutton: Aquamedia Publications, 2000.