A one-dimensional model was proposed to evaluate the performance of the ejectors. The head-loss coefficients in each component of these accessories were obtained by fitting theoretical efficiency curves to the experimental data. The calibration achieved coefficients of determination r2 varying between 0.934 and 0.999, which gave credence to considerations employed in the theoretical formulations. The theoretical performance of ejectors, for a
wide range of area ratios in the form of efficiency curves, was generated on the basis of average coefficients of head loss determined through calibration. It was found that the lower the arearatio value, the higher the range of flow ratio reached with the ejectors. Further, the maximum theoretical efficiencies of 26 and 13% were obtained with area ratios around 0.30 for the Type A and the Type B ejectors, respectively, but the latter attained its maximum efficiency with smaller flow ratio than the former. The experimental and theoretical studies showed that the Type A ejectors with area ratio of 0.35 are the most efficient design. However, it is advisable that the flow ratio on these accessories does not exceed the value of 0.50 in order to avoid efficiency declines caused by flow separation and cavitation. On the other hand, when higher flow ratios are required, the use of the Type A ejectors with area ratio of 0.20 is recommended because these
accessories can operate with flow ratios of up to 1.00 without causing efficiency declines. Therefore, it is believed that the ejectors developed in this research could replace the Venturi-type ejectors in the drip-irrigation industry in order to reduce the costs and improve the performance of chemical application systems.