| Impulse Turbine | Reaction turbine |
| 01. Energy available at the inlet is in the form of kinetic energy | 01. Energy available at the inlet is in the form of kinetic and pressure energy |
| 02. Pressure acting buckets is constant and atmospheric throughout the action of water on the runner till it is discharged to the tail race. | 02. Water enters the runner with excess pressure and hence both pressure and velocity of water change as water passes through the runner. |
| 03. Water does not fill the vanes and casings and air has free access to the buckets. | 03. Water fills completely the vanes and buckets throughout the turbine operation. |
| 04. Casing is used only to protect water from splashing and to guide water to the tail. | 04. Casing is essential to send the unit from atmospheric condition as the turbine inlet pressure is much higher than the outlet pressure. |
| 05. Turbine unit is installed above the tail race level. | 05. Turbine unit is completely submerged in water bellow the tail race level. |
| 06. Flow regulation does not result in possible loss. | 06. Flow regulation results in possible loss. |
| 07. As water passes over the guide vanes, its relative velocity reduces slightly or remains the same. | 07. As water glides over the vanes, its relative velocity increases due to continuous drop in pressure during flow through the blade passages. |
Hydraulic Machines / July 29, 2021
Comparison of Impulse and Reaction Turbines
Impulse Turbine Reaction turbine 01. Energy available at the inlet is in the form of kinetic energy 01. Energy available at the inlet is in the form of kinetic and pressure energy 02. Pressure acting buckets is constant and atmospheric throughout the action of water on the runner till it is discharged to the tail race. 02. […]