EXPLANATION:Classification of the turbine on the basis of the DIRECTION of flow through the runner:Tangential flow turbine:If the water flows along the tangent of the runner, the turbine is known as a tangential flow turbine.Radial flow turbine:If the water flows in the radial direction through the runner, the turbine is called a radial flow turbine. If the water flows from outwards to inwards radially, the turbine is known as an inward radial flow turbine, on the other hand, if water flows radially from inwards to outwards, the turbine is known as an outwards radial flow turbine.Axial flow turbine:If the water flows through the runner along the direction PARALLEL to the axis of rotation of the runner, the turbine is called an axial flow turbine.Mixed flow turbine:If the water flows through the runner in the radial direction but leaves in the direction parallel to the axis of rotation of the runner, the turbine is called a mixed flow turbine.Classification of the turbine on the basis of the type of ENERGY at inlet:Impulse turbine:If at the inlet of the turbine, the energy available is only kinetic energy, the turbine is known as an impulse turbine.Reaction turbine:If at the inlet of the turbine, the water possesses kinetic energy as well as pressure energy, the turbine is known as a reaction turbine.