Guide Blade Angle given Degree of Reaction Solution

STEP 0: Pre-Calculation Summary
Formula Used
Guide Blade Angle For Francis Trubine = acot(cot(Vane Angle at Inlet)/(1-1/(2*(1-Degree of Reaction))))
αf = acot(cot(θi)/(1-1/(2*(1-R))))
This formula uses 2 Functions, 3 Variables
Functions Used
cot - Cotangent is a trigonometric function that is defined as the ratio of the adjacent side to the opposite side in a right triangle., cot(Angle)
acot - The ACOT function calculates the arccotangent of a given number which is an angle given in radians from 0 (zero) to pi., acot(Number)
Variables Used
Guide Blade Angle For Francis Trubine - (Measured in Radian) - Guide Blade Angle For Francis Trubine is defined as the angle between the direction of the jet and the direction of motion of the plate.
Vane Angle at Inlet - (Measured in Radian) - Vane Angle at Inlet is the angle made by the relative velocity of jet with the direction of motion at inlet.
Degree of Reaction - Degree of Reaction is defined as the ratio of pressure energy change inside a runner to the total energy change inside the runner.
STEP 1: Convert Input(s) to Base Unit
Vane Angle at Inlet: 65 Degree --> 1.1344640137961 Radian (Check conversion ​here)
Degree of Reaction: 0.45 --> No Conversion Required
STEP 2: Evaluate Formula
Substituting Input Values in Formula
αf = acot(cot(θi)/(1-1/(2*(1-R)))) --> acot(cot(1.1344640137961)/(1-1/(2*(1-0.45))))
Evaluating ... ...
αf = 0.192540093735278
STEP 3: Convert Result to Output's Unit
0.192540093735278 Radian -->11.0317347580868 Degree (Check conversion ​here)
FINAL ANSWER
11.0317347580868 11.03173 Degree <-- Guide Blade Angle For Francis Trubine
(Calculation completed in 00.004 seconds)

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Guide Blade Angle given Degree of Reaction Formula

​LaTeX ​Go
Guide Blade Angle For Francis Trubine = acot(cot(Vane Angle at Inlet)/(1-1/(2*(1-Degree of Reaction))))
αf = acot(cot(θi)/(1-1/(2*(1-R))))

What is the significance of degree of reaction?

Degree of reaction is an important factor in designing the blades of a turbine, compressors, pumps and other turbo-machinery. It also tells about the efficiency of machine and is used for proper selection of a machine and it others for a required purpose. The degree of reaction contributes to the stage efficiency and thus used as a design parameter. Stages having 50% degree of reaction are used where the pressure drop is equally shared by the stator and the rotor for a turbine. This reduces the tendency of boundary layer separation from the blade surface avoiding large stagnation pressure losses. Stage having reaction less than half suggest that pressure drop or enthalpy drop in the rotor is less than the pressure drop in the stator for the turbine. Stage having reaction more than half suggest that pressure drop or enthalpy drop in the rotor is more than the pressure drop in the stator for the turbine.

What if degree of reaction is zero?

This is special case used for impulse turbine which suggest that entire pressure drop in the turbine is obtained in the stator. The stator performs a nozzle action converting pressure head to velocity head. It is difficult to achieve adiabatic expansion in the impulse stage, i.e. expansion only in the nozzle, due to irreversibility involved, in actual practice.

How to Calculate Guide Blade Angle given Degree of Reaction?

Guide Blade Angle given Degree of Reaction calculator uses Guide Blade Angle For Francis Trubine = acot(cot(Vane Angle at Inlet)/(1-1/(2*(1-Degree of Reaction)))) to calculate the Guide Blade Angle For Francis Trubine, The Guide blade angle given degree of reaction formula is used to find the guide blade angle of a Francis turbine with a right-angled outlet blade angle. Guide Blade Angle For Francis Trubine is denoted by αf symbol.

How to calculate Guide Blade Angle given Degree of Reaction using this online calculator? To use this online calculator for Guide Blade Angle given Degree of Reaction, enter Vane Angle at Inlet i) & Degree of Reaction (R) and hit the calculate button. Here is how the Guide Blade Angle given Degree of Reaction calculation can be explained with given input values -> 632.0718 = acot(cot(1.1344640137961)/(1-1/(2*(1-0.45)))).

FAQ

What is Guide Blade Angle given Degree of Reaction?
The Guide blade angle given degree of reaction formula is used to find the guide blade angle of a Francis turbine with a right-angled outlet blade angle and is represented as αf = acot(cot(θi)/(1-1/(2*(1-R)))) or Guide Blade Angle For Francis Trubine = acot(cot(Vane Angle at Inlet)/(1-1/(2*(1-Degree of Reaction)))). Vane Angle at Inlet is the angle made by the relative velocity of jet with the direction of motion at inlet & Degree of Reaction is defined as the ratio of pressure energy change inside a runner to the total energy change inside the runner.
How to calculate Guide Blade Angle given Degree of Reaction?
The Guide blade angle given degree of reaction formula is used to find the guide blade angle of a Francis turbine with a right-angled outlet blade angle is calculated using Guide Blade Angle For Francis Trubine = acot(cot(Vane Angle at Inlet)/(1-1/(2*(1-Degree of Reaction)))). To calculate Guide Blade Angle given Degree of Reaction, you need Vane Angle at Inlet i) & Degree of Reaction (R). With our tool, you need to enter the respective value for Vane Angle at Inlet & Degree of Reaction and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.
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