Answer:
i my have been taught differntly but it may be enclosure
Explanation:
Answer:
Explanation:
In a particular application involving airflow over a heated surface, the boundary layer temperature distribution, T(y), may be approximated as:
[ T(y) - Ts / T∞ - Ts ] = 1 - e^( -Pr (U∞y / v) )
where y is the distance normal to the surface and the Prandtl number, Pr = Cpu/k = 0.7, is a dimensionless fluid property. a.) If T∞ = 380 K, Ts = 320 K, and U∞/v = 3600 m-1, what is the surface heat flux? Is this into or out of the wall? (~-5000 W/m2 , ?). b.) Plot the temperature distribution for y = 0 to y = 0.002 m. Set the axes ranges from 380 to 320 for temperature and from 0 to 0.002 m for y. Be sure to evaluate properties at the film temperature.
Work, W = 277.269kJ
Internal energy, Q = 277.269kJ
<u>Explanation:</u>
Given-
Pressure, P1 = 2 bar
Temperature, T1 = 300K
Volume, V1 = 2m³
P2 = 1 bar
PV = constant
Let,
mass in kg be m
Work in kJ be W
Heat transfer in kJ be Q
R' = 8.314 kJ/kmolK
Mass of air, Mair = 28.97 kg/kmol
R = 0.289 kJ/kgK
We know,
PV = mRT
m = 5.65kg
To calculate V₂:
PV = constant = P₁V₁ = P₂V₂
P₁V₁ = P₂V₂
V₂ = 4m³
To calculate the work:
P₁V₁ = C
P₁ = C/ V₁
where limit is V₁ to V₂
To calculate heat transfer:
Q - W = Δu
Q - W = m (u₂ - u₁)
Q = W + m (u₂ - u₁)
Q = W + m X cv X (T₂ - T₁)
Since, T₁ ≈ T₂
There is no change of internal energy.
W = Q
Q = 277.269kJ
Answer:
The engine's thermal efficiency is 0.32
Explanation:
Thermal efficiency = work done ÷ quantity of heat supplied
Work done = 210 J
Quantity of heat supplied = work done + waste heat = 210 + 440 = 650 J
Thermal efficiency = 210 ÷ 650 = 0.32
Answer:
Considering the guidelines of this exercise.
The pieces produced per month are 504 000
The productivity ratio is 75%
Explanation:
To understand this answer we need to analyze the problem. First of all, we can only produce 2 batches of production by the press because we require 3 hours to set it up. So if we rest those 6 hours from the 8 of the shift we get 6, leaving 2 for an incomplete bath. So multiplying 2 batches per day of production by press we obtain 40 batches per day. So, considering we work in this factory for 21 days per month well that makes 40 x 21 making 840 then we multiply the batches for the pieces 840 x 600 obtaining 504000 pieces produced per month. To obtain the productivity ratio we need to divide the standard labor hours meaning 6 by the amount of time worked meaning 8. Obtaining 75% efficiency.
