QuestionMay 22, 2025

What are the requirements for trunk size reduction to maintain duct pressures?

What are the requirements for trunk size reduction to maintain duct pressures?
What are the requirements for trunk size reduction to maintain duct pressures?

Solution
4.2(244 votes)

Answer

Maintain duct pressures by compensating increased velocity and friction losses with fan adjustments and optimized duct design. Explanation 1. Understand Pressure Loss Pressure loss in ducts is influenced by factors like duct size, length, air velocity, and friction. Smaller ducts increase velocity, leading to higher pressure loss. 2. Apply Continuity Equation **A_1V_1 = A_2V_2** ensures mass flow rate consistency. Reducing duct size increases velocity if airflow remains constant. 3. Use Bernoulli's Principle **P_1 + \frac{1}{2}\rho V_1^2 = P_2 + \frac{1}{2}\rho V_2^2** shows that increased velocity results in decreased static pressure. 4. Consider Friction Factor **f = \frac{\Delta P}{\frac{L}{D} \cdot \frac{\rho V^2}{2}}** indicates that smaller ducts have higher friction losses due to increased surface area contact per unit volume. 5. Implement Design Adjustments To maintain pressure, compensate with fans or adjust duct layout to minimize sharp bends and transitions.

Explanation

1. Understand Pressure Loss<br /> Pressure loss in ducts is influenced by factors like duct size, length, air velocity, and friction. Smaller ducts increase velocity, leading to higher pressure loss.<br /><br />2. Apply Continuity Equation<br /> **A_1V_1 = A_2V_2** ensures mass flow rate consistency. Reducing duct size increases velocity if airflow remains constant.<br /><br />3. Use Bernoulli's Principle<br /> **P_1 + \frac{1}{2}\rho V_1^2 = P_2 + \frac{1}{2}\rho V_2^2** shows that increased velocity results in decreased static pressure.<br /><br />4. Consider Friction Factor<br /> **f = \frac{\Delta P}{\frac{L}{D} \cdot \frac{\rho V^2}{2}}** indicates that smaller ducts have higher friction losses due to increased surface area contact per unit volume.<br /><br />5. Implement Design Adjustments<br /> To maintain pressure, compensate with fans or adjust duct layout to minimize sharp bends and transitions.
Click to rate:

Similar Questions