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M. R. Zoolfakar and M. H. A. Majid
19.2.4 Crossflow Turbine
In small-scale hydropower generation, cross flow turbines (CFT), also known as
Banki or Ossberger turbines, are commonly used. The main characteristics of this
turbine are a simple construction and operation, low operating and capital expense
and fairly independent flow rate performance [12].
By using the optimum profile of the leading edges of the blade profile such as flat
tip, round tip, pointed tip, and oval tip were analyzed to ensure which one is better
in the amount of rotation [13].
A drum-shaped crossflow turbine uses an elongated, rectangular-section nozzle on
a cylindrically shaped driver, guided against curved vanes. This looks like a blower
of the “squirrel cage.” The crossflow turbine enables twice the water to flow through
the blades. The first pass is when the water flows to the inside from the outside of
the blades; the second pass is back out from the bottom. The stream is guided to a
small portion of the runner by a guide vane at the turbine entrance. The crossflow
was designed to accommodate larger flows of water and lower heads than the Pelton
turbine [14].
19.2.5 Liquid Flow
Water flow is part of the physics of water and deals with dynamics of fluids. Fluids
like gasses and moving liquids are called fluid flow. It involves moving a fluid that is
subject to unbalanced forces. The movement persists as long as there is an operation
of unbalanced forces.
For example, if you pour water from a mug, the speed of water over the lip is
very high, the lip is moderately high, and the bottom of the mug is very low. The
unbalanced force is the gravity, and as long as the water is available and the mug is
tilted, the flow continues.
For fluid flow or called flowrate, Eq. (19.1) shows the volume of fluid replaced in
a given interval of time and this is called the fluid flow equation [15].
˙
m = ρAV
(19.1)
Where, ˙
m is the mass flowrate, ρ is the density, A is the area, and V is the velocity.
For comparison of different sizes of pipe, this will result in a difference of the
water flow with the velocity as can be seen in Table 19.1.
M. R. Zoolfakar and M. H. A. Majid
19.2.4 Crossflow Turbine
In small-scale hydropower generation, cross flow turbines (CFT), also known as
Banki or Ossberger turbines, are commonly used. The main characteristics of this
turbine are a simple construction and operation, low operating and capital expense
and fairly independent flow rate performance [12].
By using the optimum profile of the leading edges of the blade profile such as flat
tip, round tip, pointed tip, and oval tip were analyzed to ensure which one is better
in the amount of rotation [13].
A drum-shaped crossflow turbine uses an elongated, rectangular-section nozzle on
a cylindrically shaped driver, guided against curved vanes. This looks like a blower
of the “squirrel cage.” The crossflow turbine enables twice the water to flow through
the blades. The first pass is when the water flows to the inside from the outside of
the blades; the second pass is back out from the bottom. The stream is guided to a
small portion of the runner by a guide vane at the turbine entrance. The crossflow
was designed to accommodate larger flows of water and lower heads than the Pelton
turbine [14].
19.2.5 Liquid Flow
Water flow is part of the physics of water and deals with dynamics of fluids. Fluids
like gasses and moving liquids are called fluid flow. It involves moving a fluid that is
subject to unbalanced forces. The movement persists as long as there is an operation
of unbalanced forces.
For example, if you pour water from a mug, the speed of water over the lip is
very high, the lip is moderately high, and the bottom of the mug is very low. The
unbalanced force is the gravity, and as long as the water is available and the mug is
tilted, the flow continues.
For fluid flow or called flowrate, Eq. (19.1) shows the volume of fluid replaced in
a given interval of time and this is called the fluid flow equation [15].
˙
m = ρAV
(19.1)
Where, ˙
m is the mass flowrate, ρ is the density, A is the area, and V is the velocity.
For comparison of different sizes of pipe, this will result in a difference of the
water flow with the velocity as can be seen in Table 19.1.