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4 years ago

Which dimensionless parameter tells whether flow disturbances will be attenuated or amplified? a. Pr b. Re C G d. St e. Fe

Engineering

1 answer:

Aleonysh [2.5K]4 years ago

7 0

Answer:

b. Re

Explanation:

Reynolds number describe the type of flow of fluid. If Reynolds number has a high value then it is called turbulent flow and if Reynolds number is low then it is called laminar flow. Reynolds number given as follows:

$Re=\dfrac{\rho VD}{\mu }$

For internal pipe flow, if Reynolds number greater than 4000 then, it is called turbulent flow and if Reynolds number less than 2000 then it is called laminar flow. The Reynolds number between 2000 to 4000 the flow is called transition flow.

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PLEASE HELP THIS IS A TEST I WAS SUPPOSE TO DO 8 HOURS AGO.

nordsb [41]

The only dimension you gave me is the width so I will work with that. If it’s asking for a smaller drawing than what is giving then the width will be 1/4 inch but if you’re saying the drawing is bigger then the width will be 4 inches

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3 years ago

Using an "AND" and an "OR", list all information (Equipment Number, Equipment Type, Seat Capacity, Fuel Capacity, and Miles per

Tomtit [17]

Answer:

Explanation :

The given information to be listed can are Equipment Number, Equipment Type, Seat Capacity, Fuel Capacity, and Miles per Gallon.

Check the attached document for the solution.

5 0

3 years ago

Please answer fast. With full step by step solution.

lina2011 [118]

Let f(z) = (4z ² + 2z) / (2z ² - 3z + 1).

First, carry out the division:

f(z) = 2 + (8z - 2) / (2z ² - 3z + 1)

Observe that

2z ² - 3z + 1 = (2z - 1) (z - 1)

so you can separate the rational part of f(z) into partial fractions. We have

(8z - 2) / (2z ² - 3z + 1) = a / (2z - 1) + b / (z - 1)

8z - 2 = a (z - 1) + b (2z - 1)

8z - 2 = (a + 2b) z - (a + b)

so that a + 2b = 8 and a + b = 2, yielding a = -4 and b = 6.

So we have

f(z) = 2 - 4 / (2z - 1) + 6 / (z - 1)

f(z) = 2 - (2/z) (1 / (1 - 1/(2z))) + (6/z) (1 / (1 - 1/z))

Recall that for |z| < 1, we have

$\displaystyle\frac1{1-z}=\sum_{n=0}^\infty z^n$

Replace z with 1/z to get

$\displaystyle\frac1{1-\frac1z}=\sum_{n=0}^\infty z^{-n}$

so that by substitution, we can write

$\displaystyle f(z) = 2 - \frac2z \sum_{n=0}^\infty (2z)^{-n} + \frac6z \sum_{n=0}^\infty z^{-n}$

Now condense f(z) into one series:

$\displaystyle f(z) = 2 - \sum_{n=0}^\infty 2^{-n+1} z^{-(n+1)} + 6 \sum_{n=0}^\infty z^{-n-1}$

$\displaystyle f(z) = 2 - \sum_{n=0}^\infty \left(6+2^{-n+1}\right) z^{-(n+1)}$

$\displaystyle f(z) = 2 - \sum_{n=1}^\infty \left(6+2^{-(n-1)+1}\right) z^{-n}$

$\displaystyle f(z) = 2 - \sum_{n=1}^\infty \left(6+2^{2-n}\right) z^{-n}$

So, the inverse Z transform of f(z) is $\boxed{6+2^{2-n}}$ .

4 0

3 years ago

For laminar flow over a hot flat plate, the local heat transfer coefficient decreases with distance because (select all that are

avanturin [10]

Answer:

hello the answer options are missing here are the options

A)The thickness of the heated region near the plate is increasing

B)The velocities near the plates are increasing

C)The fluid temperature near the plate are increasing

ANSWER : all of the above

Explanation:

Laminar flow is the flow of a type of fluid across the surface of an object following regular paths and it is unlike a turbulent flow which flows in irregular paths (encountering fluctuations)

For laminar flow over a hot flat plate, the local heat transfer coefficient decreases with distance because :

The thickness of the heated region near the plate is increasing
The velocities near the plates are increasing
The fluid temperature near the plate are increasing

5 0

3 years ago

In the truss below, the vertical reaction force at A is

Montano1993 [528]

It’s c trust just trust

7 0

3 years ago