How is the overall conductance coefficient related to the heat exchanger area?
What will be an ideal response?
The overall conductance is based on either the inside area of the tubes or the
outside area of the tubes. Thus, there are normally two conductances: one
based on the inside surface area and a conductance based on the outside
surface area. The product of the inside area times the conductance based on the
inside is the same value as the product of the outside surface area time the
conductance based on the outside area.
You might also like to view...
Brewster's Angle: When unpolarized light from air (with refractive index 1.00) strikes a piece of glass with index of refraction 1.80, the reflected light is found to be completely polarized when the angle of incidence is equal to Brewster's angle. What is the angle of refraction in this case?
Fill in the blank(s) with the appropriate word(s).
Estimate (a) the heat transfer coefficient for a spherical fuel droplet injected into a diesel engine at 80°C and 90 m/s. The oil droplet is 0.025 mm in diameter, the cylinder pressure is 4800 kPa, and the gas temperature is 944 K. (b) Estimate the time required to heat the droplet to its self-ignition temperature of 600°C.
GIVEN
• An oil droplet injected into a diesel engine
• Initial droplet temperature (To) = 80°C
• Injection velocity (Ud) = 90 m/s
• Droplet diameter (D) = 0.025 mm = 2.5 × 10–5 m
• Cylinder pressure = 4800 kPa
• Gas temperature (T?) = 944 K = 671°C FIND (a) The heat transfer coefficient ( h c) (b) The time (t) required for the drop to reach 300°C ASSUMPTIONS
• Radiative heat transfer is negligible
• The gas has the properties of air and behaves as an ideal gas
• Only the density of the gas is affected by pressure
• Variation of the thermal conductivity of the oil with temperature is negligible
• Fuel has the same properties as unused engine oil
SKETCH
Raindrops are falling straight downward. When observed from a car traveling at 55.0 mi/h, the drops streak the side window at an angle of 60.0° with the vertical. Find the speed with which the drops are falling
Since when we see Saturn's rings edge-on, they seem to disappear; they must be ________
Fill in the blank(s) with correct word