برآورد ضریب دبی جریان عبوری از دریچه‌های کشویی و قطاعی

نویسندگان

چکیده

در این پژوهش،‏ خصوصیات جریان عبوری از زیر دریچه‌های کشویی و قطاعی در شرایط جریان آزاد و مستغرق با استفاده از معادلات انرژی و مومنتم و بهره‌گیری از نتایج آزمایشگاهی سایر پژوهش‌گران مطالعه شده است. در شرایط جریان آزاد،‏ معادله‌ای برای تخمین ضریب افت انرژی دریچه ارائه و کاربرد آن در افزایش دقت برآورد ضریب دبی در شرایط جریان آزاد نشان داده شد. در شرایط جریان مستغرق نیز،‏ معادله‌ای نظری برای تخمین ضریب دبی دریچه‌های کشویی و سه نوع دریچه قطاعی با لبه لاستیکی سخت،‏ چوپوقی‌سان و لبه‌تیز گسترش داده و دیده شد در یک شرایط معین،‏ مقدار گذردهی جریان از دریچه قطاعی با لبه لاستیکی سخت نسبت به نوع لبه‌تیز و نوع چوپوقی‌سان بیشتر است. متوسط ضریب افت انرژی هر سه نوع دریچه قطاعی در شرایط جریان مستغرق وابسته به نسبت ارتفاع محور به شعاع دریچه،‏ تعیین و بر مبنای آن دقت معادله ضریب دبی بهبود یافت. با افزایش زاویه لبه دریچه،‏ مقدار ضریب دبی در یک شرایط معین کاهش می‌یابد. همچنین در یک شرایط معین،‏ میزان گذردهی جریان از هر سه نوع دریچه قطاعی بیشتر از دریچه‌های کشویی است. دیده شد استفاده از معادلات پیشنهادی ضریب دبی دریچه نوع لبه‌تیز برای دریچه‌های نوع لاستیکی سخت و چوپوقی‌سان سبب بروز خطای قابل توجه،‏ خواهد شد.

کلیدواژه‌ها


عنوان مقاله [English]

Estimating the coefficient of discharge from the sluice and radial gates

نویسندگان [English]

  • Hossein Khalili Shayan
  • Javad Farhoudi
  • Reza Roshan
چکیده [English]

In this paper, the characteristics of free and submerged outflow from the sluice and radial gates were studied by using energy and momentum equations, and experimental data of other researchers. An equation has been given to approximate the energy loss of the gate along with its application in improving the accuracy of the discharge coefficient under free flow condition has been demonstrated. A theoretical equation is also developed for estimating the discharge coefficient of sluice gates and three types of radial gates, namely Hard-Rubber, Music Note, and Sharp, under submerged flow condition. It was observed that at a certain condition, the outflow from Hard-Rubber type radial gate is larger than Music Note and Sharp types. It was realized that the mean energy loss of these types of radial gates, under submerged flow condition, is dependent on the ratio of the axial height of the gate to its radius which was used to improve the discharge coefficient. Under a certain condition, it was observed that, the discharge coefficient would decrease if the angle of gate lip is increased. It was also observed that under certain circumstances, the outflow from three types of radial gates, is much larger than sluice gates. It is noteworthy to mention that the application of the developed equation for estimating the discharge coefficient of the Sharp radial gate for Hard-Rubber and Music Note types may cause considerable errors.

In this paper, the characteristics of free and submerged outflow from the sluice and radial gates were studied by using energy and momentum equations, and experimental data of other researchers. An equation has been given to approximate the energy loss of the gate along with its application in improving the accuracy of the discharge coefficient under free flow condition has been demonstrated. A theoretical equation is also developed for estimating the discharge coefficient of sluice gates and three types of radial gates, namely Hard-Rubber, Music Note, and Sharp, under submerged flow condition. It was observed that at a certain condition, the outflow from Hard-Rubber type radial gate is larger than Music Note and Sharp types. It was realized that the mean energy loss of these types of radial gates, under submerged flow condition, is dependent on the ratio of the axial height of the gate to its radius which was used to improve the discharge coefficient. Under a certain condition, it was observed that, the discharge coefficient would decrease if the angle of gate lip is increased. It was also observed that under certain circumstances, the outflow from three types of radial gates, is much larger than sluice gates. It is noteworthy to mention that the application of the developed equation for estimating the discharge coefficient of the Sharp radial gate for Hard-Rubber and Music Note types may cause considerable errors.

In this paper, the characteristics of free and submerged outflow from the sluice and radial gates were studied by using energy and momentum equations, and experimental data of other researchers. An equation has been given to approximate the energy loss of the gate along with its application in improving the accuracy of the discharge coefficient under free flow condition has been demonstrated. A theoretical equation is also developed for estimating the discharge coefficient of sluice gates and three types of radial gates, namely Hard-Rubber, Music Note, and Sharp, under submerged flow condition. It was observed that at a certain condition, the outflow from Hard-Rubber type radial gate is larger than Music Note and Sharp types. It was realized that the mean energy loss of these types of radial gates, under submerged flow condition, is dependent on the ratio of the axial height of the gate to its radius which was used to improve the discharge coefficient. Under a certain condition, it was observed that, the discharge coefficient would decrease if the angle of gate lip is increased. It was also observed that under certain circumstances, the outflow from three types of radial gates, is much larger than sluice gates. It is noteworthy to mention that the application of the developed equation for estimating the discharge coefficient of the Sharp radial gate for Hard-Rubber and Music Note types may cause considerable errors.

In this paper, the characteristics of free and submerged outflow from the sluice and radial gates were studied by using energy and momentum equations, and experimental data of other researchers. An equation has been given to approximate the energy loss of the gate along with its application in improving the accuracy of the discharge coefficient under free flow condition has been demonstrated. A theoretical equation is also developed for estimating the discharge coefficient of sluice gates and three types of radial gates, namely Hard-Rubber, Music Note, and Sharp, under submerged flow condition. It was observed that at a certain condition, the outflow from Hard-Rubber type radial gate is larger than Music Note and Sharp types. It was realized that the mean energy loss of these types of radial gates, under submerged flow condition, is dependent on the ratio of the axial height of the gate to its radius which was used to improve the discharge coefficient. Under a certain condition, it was observed that, the discharge coefficient would decrease if the angle of gate lip is increased. It was also observed that under certain circumstances, the outflow from three types of radial gates, is much larger than sluice gates. It is noteworthy to mention that the application of the developed equation for estimating the discharge coefficient of the Sharp radial gate for Hard-Rubber and Music Note types may cause considerable errors.

کلیدواژه‌ها [English]

  • Energy-Momentum-Submerged flow-Discharge coefficient-Radial gate-Free flow-Sluice gate-