[edwinsutrisno]

My question has 2 parts:
1) In the Shear training data sets 2 and 3, the mean speed of the 10-meter anemometer is greater than the maximum speed. How can the mean be greater than the maximum speed?
2) For the same training sets, the mean speed of the 10-meter anemometer is very low throughout the data set. Temperatures are well above freezing point. Can you confirm that these data sets are healthy?

My question has 2 parts:
1) In the Shear training data sets 2 and 3, the mean speed of the 10-meter anemometer is greater than the maximum speed. How can the mean be greater than the maximum speed?
2) For the same training sets, the mean speed of the 10-meter anemometer is very low throughout the data set. Temperatures are well above freezing point. Can you confirm that these data sets are healthy?

[ebechhoefer]

Dear Sir,

I have to say that for a moment, I was concerned that I had indexed into the master data set improperly when building the Shear training data sets 2 & 3. However, this is not the case (whew!). In looking at the original data, I find that the logger (channel 6, 10 meter, max, min) did in fact have error and should be ignored. I find that the mean and standard deviation for 10 meter data, though, is correct. I apologizes for that – the rest of the channels look good.

In terms of mean wind speed on the 10 meter anemometer data being low. Yes, this is correct. Depending on site conditions (presence of trees and shrubs) the shear between 10m and 30m can very high. Essentially, that why you want to put the wind turbine up at 80m!

[rschkod]

I have another question about the shear training data at 30m and 10m. I also saw that the 10m mean value is significantly lower than the 30m mean value for sets 2 & 3, which is expected because of the low height and significant wind shear. However for shear training sets 1, 4 & 5 the 10m mean is very similar to the 30m mean. In fact, for sets 4 & 5 the 10m mean is greater than the 30m mean a significant portion of the time. This seems rather strange. Can anyone confirm this observation and if so would anyone like to comment?

[yning]

Dear bechhoefer,

Could you confirm if there is any other bad data in the training sets? It seems that PairTrng6 involves fault by visually looking at the plotted mean wind speed of the two anemometers. Could you just let us know if this data set is health or not?

Thanks

[yning]

Sir,

As mentioned in your answer, terrian conditions such as
presence of trees and shrubs have great effect on the wind speed. I wonder if all the data are collected in the same site or similar terrians?

Thanks

[Author]

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