A fluid flowing through a pipe of diameter 450 mm with velocity 3 m/s ...
Concept:
According to continuity, the liquid flow rate will be conserved.
Q1 = Q2 + Q3
In a pipe, flow rate is given by
Q = AV
Calculation:
Given V1 = 3 m/s, D1 = 450 mm, V2 = 2.5 m/s, D2 = 300 mm, D3 = 200 mm;
From continuity,
D12 V1 = D22 V2 + D32 V3
⇒ 4502 × 3 = 3002 × 2.5 + 2002 × V3
⇒ V3 = 9.56 m/s
A fluid flowing through a pipe of diameter 450 mm with velocity 3 m/s ...
Given data:
Diameter of main pipe (D1) = 450 mm
Velocity in main pipe (V1) = 3 m/s
Diameter of first pipe (D2) = 300 mm
Velocity in first pipe (V2) = 2.5 m/s
To find:
Velocity in second pipe (V3)
Using the equation of continuity, the product of the area and velocity of flow is constant.
𝐴1𝑉1 = 𝐴2𝑉2 + 𝐴3𝑉3
Where:
A1, A2, A3 = Cross-sectional areas of the main pipe, first pipe, and second pipe respectively
𝐴1 = π(D1/2)^2
𝐴2 = π(D2/2)^2
𝐴3 = π(D3/2)^2
𝐴1 = π(450/2)^2 = 159,154 mm^2
𝐴2 = π(300/2)^2 = 70,685 mm^2
To find 𝐴3, we can use the equation of continuity:
159,154 mm^2 * 3 m/s = 70,685 mm^2 * 2.5 m/s + 𝐴3 * 𝑉3
Rearranging the equation:
𝐴3 * 𝑉3 = (159,154 mm^2 * 3 m/s) - (70,685 mm^2 * 2.5 m/s)
𝐴3 * 𝑉3 = 477,462 mm^3/s - 176,713 mm^3/s
𝐴3 * 𝑉3 = 300,749 mm^3/s
Now, we need to find the cross-sectional area of the second pipe, 𝐴3.
𝐴3 = 300,749 mm^3/s / 𝑉3
To convert the flow rate from mm^3/s to m^3/s, we divide by 1,000,000:
𝐴3 = (300,749 mm^3/s / 𝑉3) / 1,000,000
The diameter of the second pipe (D3) is given as 200 mm, so we can find the cross-sectional area 𝐴3:
𝐴3 = π(200/2)^2 = 31,416 mm^2
Now, we can substitute the value of 𝐴3 in the equation:
31,416 mm^2 * 𝑉3 = 300,749 mm^3/s / 1,000,000
Simplifying the equation:
𝑉3 = (300,749 mm^3/s / 1,000,000) / 31,416 mm^2
𝑉3 ≈ 9.56 m/s
Therefore, the velocity of flow through the 200 mm diameter pipe is approximately 9.56 m/s. Hence, the correct answer is option D.