1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Kruka [31]
3 years ago
13

Water flows through a pipe at an average temperature of T[infinity] = 70°C. The inner and outer radii of the pipe are r1 = 6 cm

and r2 = 6.5 cm, respectively. The outer surface of the pipe is wrapped with a thin electric heater that consumes 300 W per m length of the pipe. The exposed surface of the heater is heavily insulated so that all heat generated in the heater is transferred to the pipe. Heat is transferred from the inner surface of the pipe to the water by convection with a heat transfer coefficient of h = 85 W/m2⋅K. Assume that the thermal conductivity is constant and the heat transfer is one-dimensional. Express the mathematical formulation (the differential equation and the boundary conditions) of the heat conduction in the pipe during steady operation.
Engineering
1 answer:
Paul [167]3 years ago
6 0

Answer:

The differential equation and the boundary conditions are;

A) -kdT(r1)/dr = h[T∞ - T(r1)]

B) -kdT(r2)/dr = q'_s = 734.56 W/m²

Explanation:

We are given;

T∞ = 70°C.

Inner radii pipe; r1 = 6cm = 0.06 m

Outer radii of pipe;r2 = 6.5cm=0.065 m

Electrical heat power; Q'_s = 300 W

Since power is 300 W per metre length, then; L = 1 m

Now, to the heat flux at the surface of the wire is given by the formula;

q'_s = Q'_s/A

Where A is area = 2πrL

We'll use r2 = 0.065 m

A = 2π(0.065) × 1 = 0.13π

Thus;

q'_s = 300/0.13π

q'_s = 734.56 W/m²

The differential equation and the boundary conditions are;

A) -kdT(r1)/dr = h[T∞ - T(r1)]

B) -kdT(r2)/dr = q'_s = 734.56 W/m²

You might be interested in
A program contains the following function definition: int cube(int number) { return number * number * number; } Write a stateme
Nonamiya [84]

Answer:

The statement can be written as

int result = cube(4);

Explanation:

A function is a block of reusable codes to perform some tasks. For example, the function in the question is to calculate the cube of a number.

A function can also operate on one or more input value (argument) and return a result. The <em>cube </em>function in the question accept one input value through its parameter <em>number </em>and the <em>number</em> will be multiplied by itself twice and return the result.  

To call a function, just simply write the function name followed with parenthesis (e.g. <em>cube()</em>). Within the parenthesis, we can include zero or one or more than one values as argument(s) (e.g. <em>cube(4)</em>).

We can then use the "=" operator to assign the return output of the function to a variable (e.g. <em>int result = cube(4)</em>)

8 0
3 years ago
Yall know what this is called?​
aliya0001 [1]

Answer:

oof no bro

Explanation:

5 0
3 years ago
Examples of reciprocating motion in daily life
bonufazy [111]

Answer:

Examples of reciprocating motion in daily life are;

1) The needles of a sewing machine

2) Electric powered reciprocating saw blade

3) The motion of a manual tire pump

Explanation:

A reciprocating motion is a motion that consists of motion of a part in an upward and downwards (\updownarrow) or in a backward and forward (↔) direction repetitively

Examples of reciprocating motion in daily life includes the reciprocating motion of the needles of a sewing machine and the reciprocating motion of the reciprocating saw and the motion of a manual tire pump

In a sewing machine, a crank shaft in between a wheel and the needle transforms the rotary motion of the wheel into reciprocating motion of the needle.

8 0
2 years ago
Nêu đặc điểm của tín hiệu PAM rời rạc dạng lưỡng cực NRZ, RZ
zhuklara [117]

Answer:

yes it is certainly good ice cream

4 0
3 years ago
What is the physical significance of the Reynolds number?. How is defined for external flow over a plate of length L.
yanalaym [24]

Answer:

Re=\dfrac{\rho\ v\ l}{\mu }

Explanation:

Reynolds number:

  Reynolds number describe the type of flow.If Reynolds number is too high then flow is called turbulent flow and Reynolds is  low then flow is called laminar flow .

Reynolds number is a dimensionless number.Reynolds number given is the ratio of inertia force to the viscous force.

Re=\dfrac{F_i}{F_v}

For plate can be given as

Re=\dfrac{\rho\ v\ l}{\mu }

Where  ρ is the density of fluid , v is the average velocity of fluid and μ is the dynamic viscosity of fluid.

Flow on plate is a external flow .The values of Reynolds number for different flow given as

Reynolds\ number\is \ >\ 5 \times 10 ^5\ then\ flow\ will\ be\ turbulent.

Reynolds\ number\is \

7 0
3 years ago
Other questions:
  • In , the industries with the most complaints to the Better Business Bureau were banks, cable and satellite television companies,
    13·1 answer
  • If there are 16 signal combinations (states) and a baud rate (number of signals/second) of 8000/second, how many bps could I sen
    7·1 answer
  • Given the following data, plot the stress-strain curves for the two unknown materials on the same set of stress-strain axes. Den
    9·1 answer
  • 4. The friction point is the point
    12·1 answer
  • Who can work on a fixed ladder that extends more than 24 feet?
    11·1 answer
  • How much heat (Btu) is prod uced by a 150-W light bulb that is on for 20-hours?
    14·1 answer
  • How do I cancel my subscription
    12·2 answers
  • ________ is the most theoretical computing discipline, focusing mostly on finding new and better ways for computers to work
    9·1 answer
  • What's the difference between a GED and a Diploma?
    12·1 answer
  • All aspects of the Kirby-Bauer test are standardized to assure reliability. What might be the consequence of pouring the plates
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!