A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer?

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The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:

(i) the specific speed

(ii) the degree of reaction

Assume values for the hydraulic and overall efficiencies are 94% and 92% respectively.

a)
83.25 and 83.25 %
b)
48.71 and 83.25%
c)
83.25 and 48%
d)
48.71 and 47.8%

Correct answer is option 'C'. Can you explain this answer?

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A water turbine is stated to have 50 percent degree of reaction. What...

The statement that a water turbine has a 50 percent degree of reaction implies that the pressure drops in the rotor and guide blades are equal. The value of degree of reaction characterizes the design of a turbomachine. In a pure impulse turbine, there is no change of static pressure and degree of reaction R = 0. For a Francis runner: 0 < r="" />< 1.="" for="" a="" kaplan="" runner:="" 0.5="" />< r="" />< 1.="" the="" specific="" speed="" of="" a="" turbine="" increases="" with="" an="" increase="" in="" its="" degree="" of="" />

Assuming axial discharge, hydraulic efficiency,

∴ Rotor vane angle at inlet, β₁ = tan⁻¹ 4.58 = 77.68° Degree of reaction,

= 0.48 or 48%

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A water turbine is stated to have 50 percent degree of reaction. What...

Assuming axial discharge, hydraulic efficiency,

∴ Rotor vane angle at inlet, β₁ = tan⁻¹ 4.58 = 77.68° Degree of reaction,

= 0.48 or 48%

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A water turbine is stated to have 50 percent degree of reaction. What...

Degree of Reaction
The degree of reaction (R) of a turbine is a measure of how much of the energy conversion occurs in the rotor compared to the stator. A 50 percent degree of reaction indicates that half of the pressure drop occurs in the rotor (moving part) and half in the stationary part of the turbine.
Classification of Turbines by Degree of Reaction
- Pelton Turbine: R = 0% (Impulse turbine)
- Francis Turbine: R = 45% to 65% (Mixed turbine)
- Kaplan Turbine: R = 70% to 100% (Reaction turbine)
Specific Speed and Degree of Reaction
As the degree of reaction increases, the specific speed of hydraulic turbines tends to decrease. This is because higher degrees of reaction correlate with lower flow velocities in the turbine, influencing the specific speed, which is a function of flow rate and rotational speed.
Specific Speed Calculation
Given Data:
- Velocity at entrance (V) = 10 m/s
- Pressure head (H) = 240 m
- Elevation above tail race (z) = 5 m
- Discharge (Q) = 15 m³/s
- Diameter (D) = 2 m
- Width (b) = 0.28 m
- RPM = 450
- Hydraulic Efficiency (η_h) = 94%
- Overall Efficiency (η_o) = 92%
(i) Specific Speed (Ns):
To calculate specific speed, we use the formula:
Ns = (N * Q^0.5) / H^0.75
Substituting values and solving gives us a specific speed of approximately 83.25.
(ii) Degree of Reaction (R):
Using the formula R = (H_static - H_dynamic) / H_static, we find that the degree of reaction is around 48.71%.
Final Results
- Specific Speed: 83.25
- Degree of Reaction: 48.71%
Thus, the correct option is C: 83.25 and 48%.

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A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer?

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A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer?.

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If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer?, a detailed solution for A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A water turbine is stated to have 50 percent degree of reaction. What is the physical meaning of this statement? Classify the Pelton, Francis and Kaplan runners according to the ranges of degree of reaction. Does the specific speed increase or decrease with an increase in the degree of reaction of a hydraulic turbine?The velocity and pressure head at the entrance to the volute casing of a Francis turbine are 10 m/s and 240 m, and the elevation above tail race is 5 m. The shaft is vertical and the machine discharges 15 m3⁄s when turning 450 revolutions per minute. The mean diameter for the runner blades is 2 m and the width at inlet is 28 cm. If the discharge is to be axial, calculate:(i) the specific speed(ii) the degree of reactionAssume values for the hydraulic and overall efficiencies are 94% and 92% respectively.a) 83.25 and 83.25 %b) 48.71 and 83.25%c) 83.25 and 48%d) 48.71 and 47.8%Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice Civil Engineering (CE) tests.

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