Ask question

Ask question

All categories

3 years ago

9

If the rotational speed of a pump motor is reduced by 35%, what is the effect on the pump performance in terms of capacity, head

, and power requirements

1 answer:

FinnZ [79.3K]3 years ago

8 0

Answer:

- the capacity of the pump reduces by 35%.

- the head gets reduced by 57%.

the power consumption by the pump is reduced by 72%

Explanation:

the pump capacity is related to the speed as speed is reduces by 35%

so new speed is (100 - 35) = 65% of orginal speed

speed Q ∝ N ⇒ Q1/Q2 = N1/N2

Q2 = (N2/N1)Q1

Q2 = (65/100)Q1

which means that the capacity of the pump is also reduces by 35%.

the head in a pump is related by

H ∝ N² ⇒ H1/H2 = N1²/N2²

H2 = (N2N1)²H1

H2 = (65/100)²H1 = 0.4225H1

so the head gets reduced by 1 - 0.4225 = 0.5775 which is 57%.

Now The power requirement of a pump is related as

P ∝ N³ ⇒ P1/P2 = N1³/N2³

P2 = (N2/N1)³P1

H2 = (65/100)²P1 = 0.274P1

So the reduction in power is 1 - 0.274 = 0.725 which is 72%

Therefore for a reduction of 35% of speed there is a reduction of 72% of the power consumption by the pump.

You might be interested in

Which type of modeling can create virtual designs that can save clients thousands of dollars?

swat32

Answer:

VR Prototyping

VR Prototyping Can Save you Thousands of Dollars.

Explanation:

there you go lad

8 0

3 years ago

For some metal alloy, a true stress of 345 MPa (50040 psi) produces a plastic true strain of 0.02. How much will a specimen of t

saveliy_v [14]

Complete Question

For some metal alloy, a true stress of 345 MPa (50040 psi) produces a plastic true strain of 0.02. How much will a specimen of this material elongate when a true stress of 411 MPa (59610 psi) is applied if the original length is 470 mm (18.50 in.)?Assume a value of 0.22 for the strain-hardening exponent, n.

Answer:

The elongation is $=21.29mm$

Explanation:

In order to gain a good understanding of this solution let define some terms

True Stress

A true stress can be defined as the quotient obtained when instantaneous applied load is divided by instantaneous cross-sectional area of a material it can be denoted as $\sigma_T$ .

True Strain

A true strain can be defined as the value obtained when the natural logarithm quotient of instantaneous gauge length divided by original gauge length of a material is being bend out of shape by a uni-axial force. it can be denoted as $\epsilon_T$ .

The mathematical relation between stress to strain on the plastic region of deformation is

$\sigma _T =K\epsilon^n_T$

Where K is a constant

n is known as the strain hardening exponent

This constant K can be obtained as follows

$K = \frac{\sigma_T}{(\epsilon_T)^n}$

No substituting $345MPa \ for \ \sigma_T, \ 0.02 \ for \ \epsilon_T , \ and \ 0.22 \ for \ n$ from the question we have

$K = \frac{345}{(0.02)^{0.22}}$

$= 815.82MPa$

Making $\epsilon_T$ the subject from the equation above

$\epsilon_T = (\frac{\sigma_T}{K} )^{\frac{1}{n} }$

$Substituting \ 411MPa \ for \ \sigma_T \ 815.82MPa \ for \ K \ and \ 0.22 \ for \ n$

$\epsilon_T = (\frac{411MPa}{815.82MPa} )^{\frac{1}{0.22} }$

$=0.0443$

From the definition we mentioned instantaneous length and this can be obtained mathematically as follows

$l_i = l_o e^{\epsilon_T}$

Where

$l_i$ is the instantaneous length

$l_o$ is the original length

$Substituting \ 470mm \ for \ l_o \ and \ 0.0443 \ for \ \epsilon_T$

$l_i = 470 * e^{0.0443}$

$=491.28mm$

We can also obtain the elongated length mathematically as follows

$Elongated \ Length =l_i - l_o$

$Substituting \ 470mm \ for l_o and \ 491.28 \ for \ l_i$

$Elongated \ Length = 491.28 - 470$

$=21.29mm$

4 0

3 years ago

cThe Mars Rover Spirit got stuck in the Martian sand. The wheels kept slipping. Attempts to free it were futile. Discuss the typ

IgorC [24]

Answer:

Improved/ advanced types of Actuators include servo systems, create a large range of actuator motion in response to the changing needs of the operational environment or process.

Actuators are local or automated suppliers of working motion.

Hydraulic and air cylinders can be classified as single-acting cylinders, meaning that the energy source result in movement in one direction and a spring is used for the other direction.

Explanation:

An actuator control system is referred to as any electronic, electrical, or electromechanical system often used to activate an actuator, control the direction as well as extent and duration of its output. Actuator control systems could take the form of extremely simple, manually-operated, start-and-stop stations, either sophisticated or programmable computer systems. The more improved/ advanced types include servo systems that produce a large range of actuator motion in response to the changing needs of the operational environment or process. This type of actuator control system uses an interface arrangement that assimilates feedback from the process or mechanism and adjusts the actuator in the right way. Most actuator systems will include at least a set of travel limits that prevent the actuator destroying itself or the secondary mechanism.

Actuators are local or automated suppliers of working motion. They are used to changes, adjust, or move a secondary mechanism, where a physical operator cannot intervene directly. They are denoted by a large range of varying types using electrical and electromagnetic, hydraulic, or pneumatic power sources to create linear or rotary outputs. One element they all have in common is the actuator control system used to start, stop, and adjust the range, speed, and duration of the working motion.

Actuators can produce a linear motion, rotary motion or oscillatory motion which means they can create motion in one direction, in a circular motion or in opposite directions at regular intervals. Hydraulic and air cylinders can be classified as single-acting cylinders, meaning that the energy source result in movement in one direction and a spring is used for the other direction.

7 0

3 years ago

1. An air standard cycle is executed within a closed piston-cylinder system and consists of three processes as follows:1-2 = con

QveST [7]

Answer:

Explanation: Here it is: 67 Hope that helps! :)

5 0

3 years ago

What is the uppermost part of the tree referred to as?

tangare [24]

Answer:

canopy I believe it is called

7 0

2 years ago

Read 2 more answers