sharp reduction and increase

[ali_dd]

Hi every body

I am working at my project of lesson. and the foolowing figure is related to my project, so I want to explain about the following figure.

As shwon in figure, at K<0.14, parameter of (D) reduces and parameter of (G) increases with decreasing parameter of K .This reduction and increase is sharp.Now I want to explain this subject.

Is the folloing sentences good?


"At k≤0.14, the reason for sharp reduction of D and sharp increase of G could be due to
the high effect of interaction between wake of upstream blade and boundary layer on the suction surface of the blade."

Is usage of "sharp reduction and increase" correct?

I am grateful that guide me about this problem.

Thanks,

Ali

 

[Skrej]

I would say "the sharp reduction of D and sharp increase of G"

 

[tedmc]

There is no sharp reduction in D at K=0.14. In fact there is a gradual increase from K = 0.16 to 0.20. The sharp reduction starts only at K=0.21.

..the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade

What do your mean by 'wake of upstream blade'?

 

[ali_dd]

There is no sharp reduction in D at K=0.14. In fact there is a gradual increase from K = 0.16 to 0.20. The sharp reduction starts only at K=0.21.

..the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade

What do your mean by 'wake of upstream blade'?

Thanks,

Yes, my mean is by 'wake of upstream blade'.

But about your answer:

Your say is correct. But, at K<0.14, there is sharp reduction in D with decreasing K.

In fact, I want to say that effect of 'wake of upstream blade' is increased with decreasing k at K<0.14.

I am grateful that guide me.

Best,

Ali

 

[MikeNewYork]

I am having trouble with your analysis of the graph. I agree that at K <0.14 D decreases. However, G increases with an increase in parameter K. It increases as K increases from 0.1 to 0.23.

 

[Raymott]

The only change I'd make is adding 'the' as mentioned above, and changing "At k≤0.14" to "At K < 0.14". Note that it's K, not k.
Obviously you are not analysing anything beyond K = 0.14 in that sentence.

 

[ali_dd]

You said that I add 'the'. Why?

my mean is the following Phrases:

"the wake of upstream blade and the boundary layer"

"the sharp reduction of D and sharp increase of G"

 

[Raymott]

You said that I add 'the'. Why?

We use articles in English.
http://englishpage.com/articles/index.htm

 

[ali_dd]

I am having trouble with your analysis of the graph. I agree that at K <0.14 D decreases. However, G increases with an increase in parameter K. It increases as K increases from 0.1 to 0.23.

only I want to explain variation of parameters of G and D at K<0.14 because the reason for this variations is important at this range, But the reason for variation is obvious beyond K = 0.14.

 

[ali_dd]

Hi friends,

Can I use words of "slop" or "rate" in this subject?

If so, How to apply?

I think that If I use word of "rate", my explanation is better in terms of scientific.

 

[Raymott]

You could possibly use 'slope'; I can't see a need for 'slop'.
You could also use 'rate', but that's going to introduce a higher level of analaysis. Your explanation will only be better if it's correct and warranted.

 

[ali_dd]

Hi friends,

I corrected the before sentences, Is the following sentence correct? If it is not , kindly suggest ways to make it clearer.

"At K<0.14, the increasing positive slope of D and increasing negative slope of G could be due to the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade as expressed previously"

Thanks,

Best

Ali

 

[Raymott]

You have to very careful about the use of "increasing slopes" - which is the danger I alluded to. You'd need to understand calculus, and apply it. The line D is increasing, but the slope is decreasing. At each point, the slope decreases further. You can measure the slope in each segment to confirm this. The slope between the first green square and the second is not increasing, but constant at approx (0.210 - 0.202) / (0.125 - 0.1), which Excel tells me is a slope of + 0.32. If you measured the next segment, you'd the find the slope was less. The slope of a straight line remains the same throughout its length, no matter what direction it's pointing in.
If you had an increasing slope, you'd get an exponential curve, not the hyperbola you have.

 

[ali_dd]

Hi,

Thanks for your answer.

Is it correct? I am grateful that guide me about the following sentences.

"By the decrease in the value of K=0.16 to 0.105,the extremely increasing positive slope of D and the extremely increasing negative slope of G could be due to the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade as expressed previously"

​

 

[ali_dd]

Hi,

In fact, low values of k caused the high effect of expressed phenomena. And also, this high effect makes that parameter of D decrease and parameter of G increase in the range of K=0.16 to 0.105.

Is not there any way that concept of the above sentences are created? The concept of above sentences is important for explaining this graf.

Thanks,

Best,

Ali

 

[tedmc]

By the decrease in the value of K=0.16 to 0.105,the extremely increasing positive slope of D and theextremely increasing negative slope of G could be due to the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade as expressed previously

As the value of K decreases from 0.16 to 0.105, there is a sharp increase in the value of D and a sharp decrease in the value of G. The two opposite effects could be due to the..

extremely increasing positive slope of D --> extremely high rate of increase --> sharp increase

 

[Raymott]

extremely increasing positive slope of D --> extremely high rate of increase --> sharp increase

The slope of the line D does not increase anywhere until the last segment. It decreases from +0.32 in the first segment to zero at the top, then becomes negative. The last segment seems a little less negative then the second last segment, hence this is the only place on line D that the slope increases.

If you were walking up a hill shaped liked the line D, You could not legitimately complain halfway to the top, "I can't handle this. The slope just keeps increasing." It doesn't.

http://en.wikipedia.org/wiki/Slope

 

[ali_dd]

Hi,

In my opinion, The word 'sharp' is used if the increase or decrease is sudden. There must be a peak in the graph to call it 'sharp'. The curve for D(the green one) is more or less a smooth one. The curve for D is also smooth in the range K=0.105-0.16.

As the value of K decreases from 0.16 to 0.105, the large increase in the value of G and the large decrease in the value of D could be due to the high effect of interaction between the wake of upstream blade and the boundary layer on the suction surface of the blade as expressed previously. would be better.

What is your opinion?

Thanks for your help.

Best,

Amin

 

[Rover_KE]

See also this thread.

You should get your answer from one forum or the other.