Explanation Write the formula for stagnation temperature ( T 0 ) . T 0 = T + V 2 2 c p (I) Here, the static temperature is T , the stagnation temperature is T 0 , the velocity is V , the specific heat at constant pressure is c p . Write the formula for stagnation pressure ( P 0 ) . P 0 P = ( T 0 T ) k / k − 1 P 0 = P ( T 0 T ) k / k − 1 (II) Here, the stagnation pressure is P 0 , the static pressure is P , and the specific heat ratio is k . Refer Table A-2, “Ideal-gas specific heats of various common gases”. The specific heat at constant pressure ( c p ) of air is 1.005 kJ/kg ⋅ °C . The specific heat ratio ( k ) is 1.4 . Conclusion: Substitute 25 ° C for T , 250 m/s for V , and 1.005 kJ/kg ⋅ °C for c p in Equation (I). T 0 = 25 ° C + ( 250 m/s ) 2 2 ( 1.005 kJ/kg ⋅ °C ) = 25 ° C + 62500 m 2 /s 2 × 1 kJ/kg 1000 m 2 /s 2 2

9th Edition

ISBN: 9781259822674

Author: Yunus A. Cengel Dr., Michael A. Boles

Publisher: McGraw-Hill Education

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Chapter 17.7, Problem 147FEP

To determine

The stagnation pressure of air from the following:

(a) 184 kPa

(b) 96 kPa

(c) 161 kPa

(d) 122 kPa

(e) 135 kPa

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Chapter 17.7, Problem 146FEP

Chapter 17.7, Problem 148FEP

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The stagnation pressure of air from the following: (a) 184 kPa (b) 96 kPa (c) 161 kPa (d) 122 kPa (e) 135 kPa

Solution Summary: The author explains the static temperature, velocity, and specific heat at constant pressure of air.