* brown@erc

- ltd.com, 949 583 1197 x 101 

### Nozzle Characterization:

Amerex Nozzle Droplet Size Classification

prepared for

Amerex

Christopher Brown*, Ulises Mondragon

, Chris Antes, and Vincent McDonell

23342 South Pointe Drive, Suite E

Laguna Hills, CA 9 2653

Phone: (949) 583

- 1197

FAX: (949) 583

- 1198

1 0 Dec ember 2011

Report ERC

- Amerex1

- 11

- 1(a)

Amerex PO Number SPS786 

## E NERGY 

## R ESEARCH 

## C

ONSULTANTSEnergy Research Consultants Droplet Size Classification Amerex PO number SPS786

ii The recipient and reader of this report agrees to Hold Harmless Energy Plus Ltd doing

business as Energy Research Consult ants (ERC) and the Officers, Directors, Agents,

and Employees from and against any and all liabilities and claims made by other

individuals or entities as a result of using the information contained in this report.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

iii 

## Table of Contents

1 Summary

................................ ................................ ................................ ............................ 1

2 Approach

................................ ................................ ................................ ............................ 1

2.1 Size Bins

................................ ................................ ................................ ...................... 1

2.2 Probe Volume Correction

................................ ................................ ............................. 1

2.3 Curve Fit

................................ ................................ ................................ ...................... 1

2.4 Other Comments on Approach

................................ ................................ ..................... 2

3 Results

................................ ................................ ................................ ................................ 5

3.1 Non Area Weighted Results

................................ ................................ ......................... 5

3.2 Area Weighted Results

................................ ................................ ................................ 5

3.3 Comments on Results

................................ ................................ ................................ .. 5

4 Raw Data

................................ ................................ ................................ ............................ 7

5 References

................................ ................................ ................................ ......................... 8



## List of F igures

Figure 1. Measurement Locations.

................................ ................................ ............................ 2

Figure 2. Droplet Size Averages versus Radial Position For All Droplet Size Classes.

.............. 3

Figure 3. Sample Log Normal Curve Fit.

................................ ................................ ................... 4

Figure 4. Area Weighting.

................................ ................................ ................................ .......... 6

Figure 5. Sample Raw Data.

................................ ................................ ................................ ..... 7



## List of Tables

Table 1. Size Bins.

................................ ................................ ................................ .................... 2

Table 2. Size Classified Results by Number.

................................ ................................ ............. 6

Table 2. Size Classified Results by Percent.

................................ ................................ ............. 6Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

1 

## 1 Summary

This report summarizes the droplet size classification of previously obtained size

d ata collected under a separate PO from Seal Seat

.



## 2 Approach

Droplet size data were previously obtained on two Amerex nozzles provided by

Seal Seat. These measurements were collected under a separate PO from Seal Seat.

Report number ERC

- SealSeat2

- 11

- 1 (a) in the Reference section provides additional

details.



### 2.1 Size Bins

Amerex requested the droplet sizes be classified using the size bins shown in

Table 1

. Four (4) radial locations at each of three (3) axial locations for a total of 12

locations were sampled in the spray as is shown in Figure 1

. The droplet counts

obtained within a particular bin size were added up for all 12 locations.

The previous average size results for all droplet size class es are shown in Figure

2 for reference.



### 2.2 Probe Volume Correction

Probe volume correction (PVC) was employed to compensate the measured size

distribution for the smaller effective sample volume associated with the smaller drops

due to the Gaussian intensity profile of the laser beam. PVC represents the counts that

would be obtained if all drop sizes had the same sample volume.



### 2.3 Curve Fit

The lower theoretical detection limit of the phase Doppler instrument is

approximately 0.5 microns. A log normal curve fit was applied to the data in order to

estimate the counts below 0.5 microns. A sample fit is shown in Figure 3 . Other curve

fits were considered such as Rosin Rammler, but the log normal was fo und to best fit

the number distribution , which is the distribution of interest to this analysis

.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

2 

### 2.4 Other Comments on Approach

D espite the approximate 0.5 micron lower detection limit, the phase Doppler

instrument was the ideal choice to make these mea surements within the available time

and budget scopes.

An additional radial location was sampled on the other side of the centerline was

obtained at each axial location. These three (3) locations were not included in the

calculation so as to not bias t he results toward the center of the spray.

The budget for the current size classification did not allow for calculations on the

second nozzle. The mean droplet sizes were similar ( see report number ERC

SealSeat2

- 11

- 1(a) ) , hence the size classified resul ts are expected to be similar.

Table 1 . Size Bins.

Left Side of Size Bin

(microns) Right Side of Size Bin

(microns)

0.00 0.1 0

0.1 0 0.25

0.25 0.5 0

0.5 0 1 .00

1 .00 2.5 0

2.5 0 5 .00

5 .00 250.00

Figure 1 . Measurement Locations.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

3 a) Nozzle 1

b) Nozzle 2

Figure 2 . Droplet Size Averages versus Radial Position For All Droplet Size Classes

.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

4 Figure 3

. Sample Log Normal Curve Fit.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

5 

## 3 Results

The size classified results are summarized by number in Table 2 and by percent

in Table 3

.



### 3.1 Non Area Weighted Results

Four (4) radial locations at each of three (3) axial locations for a total of 12

locations were sampled in the spray as is shown in Figure 1 . The droplet counts

obtained within a particular bin size were summed up for all 12 locations. The total

counts for each size bin are presented in Table 2 and percentages of the total count are

shown in Table 3

.



### 3.2 Area Weighted Results

The calculations were performed again with area weighting. Area weighting

attempts to extend the results from a single radial profile to reflect the total spray. Area

weighting weights the mea surement at each radial position by the area which it

represents, that is, r 2 weighting. Measurements from the center receive less weighting

because they represent less area, measurements near the edge receive more weighting

because the y represent more are a. See the sketch in Figure 4

. The total counts for

each size bin are presented in Table 2 and percentages of the total count are shown in

Table 3

.



### 3.3 Comments on Results

Please keep the following considerations in mind when interpreting the present

results.

As noted above, the lower detection limit of the phase Doppler instrument is

approximately 0.5 microns. A log normal distribution fit was applied to the data in order

to estimate the counts in these lower size bins.

The data wer e obtained in a spray chamber with approximately 1 m/s coflowing

air in order to control droplet recirculation and prevent droplets from being measured

twice. This is conventional practice. The coflowing air likely allows for significant

evaporation of t he very smallest droplets. Any d roplets that evaporate prior to reaching

the measurement volume are not measured. In practical conditions such as the

confined space of a military vehicle, less evaporation would be expected and larger

quantities of smalle r particles may be found

.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

6 Table 2 . Size Classified Results by Number

.

Left Side

Size Bin

(microns) Right Side

Size Bin

(microns) Non Area Weighted

Number

( count ) Area Weighted

Number

(count )

0.00 0.1 0 7.2090E

- 20 1.2040E

- 14

0.1 0 0.25 1.8196E

- 14 1.3248E

- 09

0.25 0.5 0 2.0662E

- 10 8.2232E

- 06

0.5 0 1 .00 8.4228E

- 07 0.03110774

1 .00 2.5 0 0.00884 323.86607

2.5 0 5 .00 7.26232 104,260

5 .00 250.00 634,444 4,434,949,108

TOTAL 634,452 4,435,053,692

Table 3 . Size Classified Results by Percent.

Left Side

Size Bin

(microns) Right Side

Size Bin

(microns) Non Area Weighted

Number Percent

(%) Area Weighted

Number Percent

(%)

0.00 0.1 0 1.1363E

- 23 2.7147E

- 22

0.1 0 0.25 2.8679E

- 18 2.9870E

- 17

0.25 0.5 0 3.2567E

- 14 1.8541E

- 13

0.5 0 1 .00 1.3276E

- 10 7.0141E

- 10

1 .00 2.5 0 1.3939E

- 06 7.3024E

- 06

2.5 0 5 .00 1.1447E

- 03 2.3508E

- 03

5 .00 250.00 99.9989 99.9976

TOTAL 100.00 100.00

Figure 4 . Area Weighting.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

7 

## 4 Raw Data

Raw data in csv (co mma separated value) format will be provided electronically.

An example is shown in Figure 5

.

Size Bin

(microns) Uncorrected Count Corrected Count

0.5 0 0

1.5 6 42

2.5 4 28

3.5 9 63

4.5 22 154

5.5 25 175

6.5 47 329

7.5 56 392

8.5 88 616

9.5 133 931

10.5 195 1365

etc etc etc

Figure 5 . Sample Raw Data.Energy Research Consultants Droplet Size Classification Amerex PO number SPS786

8 

## 5 References

Nozzle Characterization: Droplet Sizing (Amerex Nozzles 1 and 2) (Summary Report),

prepared for Seal Seat, Christopher Bro wn , Ulises Mondragon, Chris Antes, and

Vincent McDonell , Energy Research Consultants, 15 September 2011

, Report ERC

SealSeat2

- 11

- 1(a)

, Seal Seat PO Number 7291871

.