Answer:
i) h-bar-L = 4110 W/m^2K
ii ) h-bar-L = 4490 W/m^2K
iii) h-bar-L = 5072 W/m^2K
Explanation:
Given:-
- The temperature of water, T = 27°C
- The velocity of fluid flow, U∞ = 2m/s
- The length of the flat place, L = 1 m
Solution:-
- Using table A-6, to determine the properties of water:
Density ρ = 997 kg/m^3
Dynamic viscosity ν = 0.858*10^-6 m^2/s
Pr = 583 , k = 0.613 W/m.K
- The reynold's number for full length (L = 1m):
Re = U∞*L / ν
Re = (2)*(1) / (0.858*10^-6)
Re = 2.33*10^6
- The boundary layer is mixed with Rex,c = 5*10^5. Evaluate the critical length (xc):
xc = L* ( Rex,c / Re )
= (5*10^5 / 2.33*10^6 )
= 0.215 m
a) Using "IHT correlation tool, External Flow, Local coefficients for laminar or Turbulent flows", h (x) was evaluated and plotted with critical Reynolds number for all 3 cases: (i) 5 × 10^5, (ii) 3 × 10^5, and (iii) 0 (the flow is fully turbulent). - (See attachment 1)
b) Using "IHT correlation tool, External Flow, Average coefficients for laminar or Mixed flows", h - bar- (x) was evaluated and plotted with critical Reynolds number for all 3 cases: (i) 5 × 10^5, (ii) 3 × 10^5, and (iii) 0 (the flow is fully turbulent). - (See attachment 2)
c) The average convection coefficient for the plate can be determined from the graphs presented in (Attachments 1 and 2). Since,
h-bar-L = h-bar-x(L)
The values for the flow conditions are:
( i) h-bar-L = 4110, ii ) h-bar-L = 4490 , iii) h-bar-L = 5072 ) W/m^2K
Answer:
X_cp = c/2
Explanation:
We are given;
Chord = c
Angle of attack = α
p u (s) = c 1
p1(s)=c2,
and c2 > c1
First of all, we need to find the resultant normal force on the plate and the total moment about leading edge.
I've attached the solution
Answer:
Ps=19.62N
Explanation:
The detailed explanation of answer is given in attached files.
Answer:
Magnitude of force P = 25715.1517 N
Explanation:
Given - The wires each have a diameter of 12 mm, length of 0.6 m, and are made from 304 stainless steel.
To find - Determine the magnitude of force P so that the rigid beam tilts 0.015∘.
Proof -
Given that,
Diameter = 12 mm = 0.012 m
Length = 0.6 m
= 0.015°
Youngs modulus of elasticity of 34 stainless steel is 193 GPa
Now,
By applying the conditions of equilibrium, we have
∑fₓ = 0, ∑ = 0, ∑M = 0
If ∑ = 0
⇒×0.9 - P × 0.6 = 0
⇒×3 - P × 2 = 0
⇒ =
If ∑ = 0
⇒×0.9 = P × 0.3
⇒ ×3 = P
⇒ =
Now,
Area, A = = 1.3097 × 10⁻⁴ m²
We know that,
Change in Length , =
Now,
= 9.1626 × 10⁻⁹ P
= 1.83253 × 10⁻⁸ P
Given that,
= 0.015°
⇒ = 2.618 × 10⁻⁴ rad
So,
⇒2.618 × 10⁻⁴ = ( 1.83253 × 10⁻⁸ P - 9.1626 × 10⁻⁹ P) / 0.9
⇒P = 25715.1517 N
∴ we get
Magnitude of force P = 25715.1517 N
Answer:
%
Explanation:
Determine the initial velocity
= 19.89 m/s
final velocity
=8.84 m/s
total mechanical energy is given as
Shaft power
mechanical efficiency
%
Answer:
Not reasonable.
Explanation:
To solve this problem it is necessary to take into account the concepts related to the performance of a reversible refrigerator. The coefficient of performance is basically defined as the ratio between the heating or cooling provided and the electricity consumed. The higher coefficients are equivalent to lower operating costs. The coefficient can be greater than 1, because it is a percentage of the output: losses, other than the thermal efficiency ratio: input energy. For a reversible refrigerator the coefficient is given by
Where,
High temperature
Low Temperature
With our values previous given we can find it:
With these values we can now calculate the coefficient of performance:
At the same time we can calculate the work consumption of the refrigerator, this is
Where,
Required power input
t = time to remove heat from a cool to water medium
In this way we can calculate the coefficient of the refrigerator directly:
Where,
Q = Amoun of heat rejected
Comparing the values of both coefficients we have that the experiments are NOT reasonable, because the coefficient of a refrigerator is high compared to coefficient of reversible refrigerator.