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19892
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Subject: Agricultural Engineering × End date: 1989 × Start date: 1989 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Design, fabrication and evaluation of the performance characteristics of hydraulic ram by varying the various parameters
    (Department of Land and Water Resources and Conservation Engineering, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1989) Suseela, P; KAU; George, T P
    In India, the agricultural production in many areas especially in hilly areas is very much affected by the non – availability of adequate power to lift water for irrigation. Main problems in enhancing irrigation facilities in hilly regions are their highly uneven topography and non availability of conventional sources of energy. The rapid depletion of conventional sources of energy and increasing demands have now focussed the attention on the need for developing a new economical and effective water lifting device which does not use the conventional sources of energy. A hydraulic ram may meet these requirements in hilly regions and can lift water without any external source of energy in the form of fuel or electricity. A hydraulic ram was designed and fabricated with cheap and commercially available materials. A constant supply head of 1.955 m was provided. Ram was designed for a maximum delivery head of 10 m. Provisions were given to vary the weight and stroke length of both the delivery valve and waste valve. A flange joint was incorporated valve and waste valve. A flange joint was incorporated between the delivery valve and air chamber to facilitate the quick opening and reinstallation of air chamber. Air chamber was fabricated with provisions to alter the volume, by changing the length of air chamber – the diameter of the air chamber was kept constant. The performance of hydraulic ram was evaluated mainly observing the delivery head – delivery discharge relationships. In each case the efficiency of the ram was evaluated. Typical performance characteristic curves were plotted for each of the changes in the conditions of operation. Effect of volume of air chamber on the performance of hydraulic ram was studied. The study revealed that the efficiency of the ram increases 1. as the weight of delivery valve increases 2. as the stroke length of delivery valve decreases 3. as the volume of air chamber increases 4. as the stroke length of waste valve decreases There is a steep reduction in delivery discharge with unit increase in delivery head. For a particular combination of waste valve, delivery valve and volume of air chamber, the maximum efficiency occurs at a moderate delivery head. For an increase in the stroke length of waste valve, there is a large reduction in best frequency. The beat frequency increases as the delivery head increases. The rate of decrease of best frequency with respect to the stroke length is higher for lower weights of was to valve. The ram stops functioning at certain low value of delivery head. This low valve of delivery head increases with increase in weight of delivery valve. Corresponding to a certain weight of delivery valve, there is a minimum weight of waste valve at which the ram functions satisfactorily. Further investigations are necessary to standardise different parts of the hydraulic rams for optimising their performance under varying conditions.
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    ThesisItemOpen Access
    Design, fabrication and testing of a savonius type windmill with a deflector augmentor
    (Department of Farm Power Machinery and Energy, Kelappaji College of Agricultural Engineering and Technology, Tavanur, 1989) Satyajith, Mathew; KAU; Wilson, K I
    The study was conducted with the objectives of developing and testing a savonius wind mill and analysing the effect of a deflector augmentor on the performance characteristics of the rotor. The wind mill was consisted of two rotors of 2 m x 3 m size fixed one below the other at 90 degree out of phase. A 100 mm galvanised iron pipe of 12 m length acts as the shaft. The shaft passes through two ‘30220’ taper roller bearings. Lower bearing was fixed on a I m x I m x I m foundation and the upper bearing was positioned by four 4 mm guy wires. The guy wires were equidistant and forms an angle of 45 degree with the shaft. This wind mill was tested under field conditions. Power developed by the wind mill was calculated by measuring the torque and rotor speed, and power delivered to the rotor was calculated by taking corresponding wind velocity. The coefficient of power and coefficient torque were calculated for different tip speed ratios. The wind mill was found to attain a maximum coefficient of power 0.155 at a tip speed ratio 1.0. Maximum torque coefficient attained was 0.185 at a tip speed ratio 0.75 Optimum tip speed ratio of the wind mill was found to be in a range of 0.5 to 0.9. A deflector augmentor of 6.93 m2 effective wind facing area was fixed at an angle of 60 degree with the wind direction. Wind mill was again tested with the deflector augmentor. Power coefficient was found to attain a maximum value of 0.32 at a tip speed ratio 1.54. The maximum torque coefficient was 0.385 at a tip speed ratio of 0.56. Optimum tip speed ratio of the wind mill with the deflector augmentor was found to be in a range of 0.5 to 1.5. When the deflector augmentor was attached to the wind mill, power coefficient was increased by 106.5 percent and torque coefficient was increased by 108 percent. The wind mill was found to work in higher tip speed ratios. The cut in velocity was reduced from 2.4 m/s to 1.4 m/s. Cost of operation of the wind mill was Rs.1.45 per bhp.hr which is comparable with diesel and electric power.