TY - JOUR T1 - Numerical and Experimental Analysis of Hydro Screw Turbine with Variable Pitch TT - بررسی عددی و تجربی رفتار توربین هیدرواسکرو با گام متغیر JF - mdrsjrns JO - mdrsjrns VL - 19 IS - 2 UR - http://mme.modares.ac.ir/article-15-23065-en.html Y1 - 2019 SP - 457 EP - 466 KW - Variable Pitch KW - Screw KW - Low Head KW - Archimedes N2 - Hydro screw is a small micro-hydro turbine. Due to increase in demand for clean energy production, a comprehensive project at the Iranian Research Organization for Science and Technology (IROST) for the design and construction of very small turbines (micro-turbines), including hydro screw, has been developed. Hydro screw is suitable for a low head and discharge that does not have a guide vane and draft tube; thus, it is simple, small, inexpensive, and portable. This turbine, with a 15 cm blade diameter, can generate power up to 2 kW. Hydro screw blade is inspired by the Archimedes turbine, and difference between them is that the blade pitch of hydro screw is variable and horizontally mounted. In this project, the effect of spiral variable pitch on turbine has been studied numerically. Based on the results, it was found that the turbine had the best efficiency at a spiral pitch of 1.5. Subsequently, the small model of hydro screw was made and tested in the laboratory. The results of this study have been presented in the form of standard curves of turbine performance and the accuracy of the results has been proved by comparison of numerical and experimental results. The results show the integrity of the numerical calculations and, therefore, they can be used in line with next turbine studies. The results indicate that the maximum turbine output is between 62% and 68%. M3 ER -