Answer:
Departure rate = 7.65 vehicle/min
Explanation:
See the attached file for the calculation.
The heat transfer coefficient for air flowing over asphere is to be determined by observing temperature-time history of a sphere
fabricated from pure copper. The sphere, which is 12.7 mm in diameter, is at 66oC before it is inserted into an airstream having a temperature of 27oC. A thermocouple on the outer surface of the sphere indicates 55oC 69 s after the sphere is inserted. (a) Assume and then justify that the sphere behaves as spacewise isothermal object. (b) Calculate the heat transfer coefficient, h. (c) Calculate the amount of heat lost by the sphere during this time, i.e., 69 s.
1 answer:
You might be interested in
Answer:
The specific volume is reduced in 80 per cent due to isothermal compression.
Specific enthalpy remains constant.
Explanation:
Let suppose that neon behaves ideally, the equation of state for ideal gases is:
Where:
- Pressure, measured in kilopascals.
- Volume, measured in cubic meters.
- Molar quantity, measured in kilomoles,
- Temperature, measured in kelvins.
- Ideal gas constant, measured in
.
On the other hand, the molar quantity () and specific volume (
), measured in cubic meter per kilogram, are defined as:
and
Where:
- Mass of neon, measured in kilograms.
- Molar mass of neon, measured in kilograms per kilomoles.
After replacing in the equation of state, the resulting expression is therefore simplified in term of specific volume:
Since the neon is compressed isothermally, the following relation is constructed herein:
Where:
,
- Initial and final pressure, measured in kilopascals.
,
- Initial and final specific volume, measured in cubic meters per kilogram.
The change in specific volume is given by the following expression:
Given that and
, the change in specific volume is:
The specific volume is reduced in 80 per cent due to isothermal compression.
Under the ideal gas supposition, specific enthalpy is only function of temperature, as neon experiments an isothermal process, temperature remains constant and, hence, there is no change in specific enthalpy.
Specific enthalpy remains constant.