Int’l Ground Boom Driftl Ground Boom DriftModel DevelopmentModel DevelopmentDavid Valcore, Valcore Consulting,David Valcore, Valcore Consulting,H. Thistle, USDAH. Thistle, USDA-FS Program Manager,FS Program Manager,Forest Health ProtectionForest Health ProtectionClare Butler Ellis, Silsoe Applic. Unit,Clare Butler Ellis, Silsoe Applic. Unit,NIAD-TAGEMPM July 27, 20102BackgroundBackgroundCurrent global and EPACurrent global and EPA’s regulatory ground boom sprays regulatory ground boom spraydrift models are all empirical curve fits to field data fordrift models are all empirical curve fits to field data fordeposition predictionsdeposition predictions–AgDRIFT, PMRA (WolfAgDRIFT, PMRA (Wolf-Campbell), BBA (GanzelmeirCampbell), BBA (Ganzelmeir-Rottamen), IDEFCs (NE)Rottamen), IDEFCs (NE)Empirical fits limit mitigation options, e.g. original SAPEmpirical fits limit mitigation options, e.g. original SAPreview of AgDRIFT (SDTF data) pointed out inability toreview of AgDRIFT (SDTF data) pointed out inability toaccount for wind speed.account for wind speed.Acknowledged need for longer range drift predictions forAcknowledged need for longer range drift predictions forEndg Species Assessments; [AgDRIFT max 300m, othersEndg Species Assessments; [AgDRIFT max 300m, others20-120m]Past efforts of AGDISP ground and early Silsoe (UK) hadPast efforts of AGDISP ground and early Silsoe (UK) hadlimited fits to field data.limited fits to field data.Desire to evaluate mitigation options for EPA DriftDesire to evaluate mitigation options for EPA DriftReduction Technology (DRT) programReduction Technology (DRT) programEMPM July 27, 20103‘Silsoe’Drift ModelDrift ModelChosen per consensus as initial attempt at robustChosen per consensus as initial attempt at robustmechanistic model, with potential for long rangemechanistic model, with potential for long rangepredictions and mitigation options under EPA DRTpredictions and mitigation options under EPA DRTprogramprogramMiller, P.C.H.; Hadfield, D.J. (1989) A simulation model of spraMiller, P.C.H.; Hadfield, D.J. (1989) A simulation model of spraydrift from hydraulic nozzles.drift from hydraulic nozzles. 

# Journal of Agricultural Engineering Journal of Agricultural Engineering

Research Research, 42, 135, 42, 135-142enhancements include multiple nozzle boom, sprayerenhancements include multiple nozzle boom, sprayerspeed effects, evaporation module, sprayer effect,speed effects, evaporation module, sprayer effect,probabilistic inputsprobabilistic inputsInitial development under UK Pest Safety Dir. Project,Initial development under UK Pest Safety Dir. Project,BREAM, for bystander exposure , vapor drift addition,BREAM, for bystander exposure , vapor drift addition,possible sprayer CFD model input/enhancement.possible sprayer CFD model input/enhancement.Ref C. Butler Ellis, C., (2008) The BREAM projectRef C. Butler Ellis, C., (2008) The BREAM project––modeldevelopments, TPSA Drift Modeling Workshop, Ashville, NCdevelopments, TPSA Drift Modeling Workshop, Ashville, NCEMPM July 27, 20104Global Effort, Ad hoc Prelim MtgGlobal Effort, Ad hoc Prelim MtgUSDA FS and ARS, UK Silsoe Applic. Unit , CLA,USDA FS and ARS, UK Silsoe Applic. Unit , CLA,UC Davis, Lincoln Ventures NZ, SDTF, Agric, andUC Davis, Lincoln Ventures NZ, SDTF, Agric, andFood Canada.Food Canada.Initial plans reported to EMPM Sept. 2009Initial plans reported to EMPM Sept. 2009–Status UpdateStatus UpdateSensitivity AnalysisSensitivity Analysis–key parameterskey parametersPrelim. model comparisons to SDTF and PMRA / WolfPrelim. model comparisons to SDTF and PMRA / Wolfdata setsdata setsInvestigating multiple nozzle environ effect vs. singleInvestigating multiple nozzle environ effect vs. singlenozzle wind tunnelnozzle wind tunnelBelgium Un. Leven ~120 reps of field testing for driftBelgium Un. Leven ~120 reps of field testing for driftdeposition to 30 m, acceptable protocol for usedeposition to 30 m, acceptable protocol for useEMPM July 27, 20105Comparison with subset of Spray Drift TaskComparison with subset of Spray Drift TaskForce (SDTF) dataForce (SDTF) dataDifferent nozzle from previous validation workDifferent nozzle from previous validation work–80 04 (flat fan)80 04 (flat fan)Measurements relating to specific nozzleMeasurements relating to specific nozzleNo data for porosity/velocity factorsNo data for porosity/velocity factorsBase on previous work with 110 03 nozzleBase on previous work with 110 03 nozzleDifferent spray liquidDifferent spray liquidFormulation not available in UK so use blank ECFormulation not available in UK so use blank ECLimited no. droplets, for run time = unsmoothedLimited no. droplets, for run time = unsmoothedcurveEMPM July 27, 20106Comparisons to SDTF DataComparisons to SDTF DataWind 3.9 m/sWind 3.9 m/s(FF8004, 50 cm boom 5 mph)(FF8004, 50 cm boom 5 mph)Run 0903 rep 30.010.11100 20 40 60 80 100 120 140 160 180 200Distance downwind, m

% app volSDTF dataSLAB + evapAGDISPDifferent nozzle from previous validationwork – 80 04Measurements relating to specificnozzleNo data for porosity/velocity factorsBase on previous work with 110 03nozzleDifferent spray liquidFormulation not available in UK so useblank ECEMPM July 27, 20107Current Silsoe vs. SDTF trt at 50Current Silsoe vs. SDTF trt at 50”boom09 07 v rep 4 - 50" boom height0.010.11101000 20 40 60 80 100 120 140 160 180 200Distance downwind

% App volEMPM July 27, 20108Comparisons vs. SDTF data to 400 mComparisons vs. SDTF data to 400 mComparison of Silsoe model and Agdrift up to 400 m for 09 06rep 100.20.40.60.811.21.40 50 100 150 200 250 300 350 400 450 500Distance downwind, m

% App volSilsoe modelAGDISPsdtf dataEMPM July 27, 20109Comparison over all SDTF standard runsComparison over all SDTF standard runs0.010.11100.01 0.1 1 10Measured ground deposit, ml/m2

Predicted ground deposit, ml/m20.0010.010.11100.001 0.01 0.1 1Measured ground deposit, % applied

Predicted deposit, % appliedEMPM July 27, 201010Sensitivity AnalysisSensitivity AnalysisLarge number of inputs needed to run modelLarge number of inputs needed to run modelSome assumptions and approximations areSome assumptions and approximations areincluded in the modelincluded in the modelAre improvements needed to the model toAre improvements needed to the model toadequately represent the processes involved?adequately represent the processes involved?Understand important parametersUnderstand important parametersHow accurately do the input parameters need toHow accurately do the input parameters need tobe measured?be measured?EMPM July 27, 201011Nozzle ParametersNozzle ParametersParameterParameterDescriptionDescriptionBeta Initial entrained air velocity as a fraction of liquid sheet velocityDropmax Number of droplets per size binMdvMinimum droplet volume as fraction of originalMds, μm Minimum droplet sizeC1, degrees Half wide angleC2, degrees Half narrow angleVl0, m/s Liquid sheet velocityr0, mm Initial distance from nozzleSSFx Air velocity scaling factor (x-direction)SSFy Air velocity scaling factor (y-direction)Lpx, m Porosity length, x -directionLpy, m Porosity length, y -directionEMPM July 27, 201012Nozzle / Environmental ParametersNozzle / Environmental ParametersParameterParameterDescriptionDescriptionBin width,Bin width,μmdropsize step/group widthdropsize step/group widthDroplet size distributionDroplet size distributionDroplet velocity, m/sDroplet velocity, m/sWbd, degrees CWbd, degrees CWet bulb depressionWet bulb depressionh, mHeight of boom above cropHeight of boom above cropWs, m/sWs, m/sWind speed at 3 m above cropWind speed at 3 m above cropFs, km/hFs, km/hForward speed of sprayerForward speed of sprayerEMPM July 27, 201013Sensitivity to Nozzle porositySensitivity to Nozzle porosityparameters, Minparameters, Min-Max inputMax input0.010.1110050100150200250Distance downwind, m

Ground deposit, ml/m2Model prediction, original parametersSDTF dataModel prediction, minimum driftparametersEMPM July 27, 201014Humidity EffectHumidity Effect(0-8owbd)0.00010.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumewbd = 0 deg Cwbd = 4 deg Cwbd = 8 deg CEMPM July 27, 201015Effect of minimum drop volumeEffect of minimum drop volume(% non-volatile)volatile)0.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumemdv = 0.1mdv = 0.02mdv = 0.2EMPM July 27, 201016Boom height effectBoom height effect0.00010.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumeBoom ht = 0.7 mBoom ht = 0.4 mBoom height = 1.1 mEMPM July 27, 201017Effect of Wind SpeedEffect of Wind Speed0.00010.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumeWind speed = 3.0 m/sWind speed = 1.0 m/sWind speed = 5.0 m/sEMPM July 27, 201018Effect of Beta (entrained air velocity)Effect of Beta (entrained air velocity)0.00010.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumeBeta = 1Beta = 0.5Power (Beta = 1)Power (Beta = 0.5)EMPM July 27, 201019Effect of droplet size distributionEffect of droplet size distribution0.00010.0010.010.110 50 100 150 200Distance downwind, m

Ground deposits, % applied volumeDroplet size distribution as measured, VMD= 230 umLarger droplets, VMD = 255 umSmaller droplets, VMD = 200 umEMPM July 27, 201020SummarySummaryGround deposits predicted by the Silsoe spray drift model show aGround deposits predicted by the Silsoe spray drift model show agoodcomparison with data from the SDTF and potential for the DRT procomparison with data from the SDTF and potential for the DRT program.Tendency for the model to over predictTendency for the model to over predict-greatest nearer the sprayergreatest nearer the sprayerCould potentially be improved by more reliable input data and improvements toprovements tomodeling spray characteristics.modeling spray characteristics.A sensitivity analysis showed the most important parameters forA sensitivity analysis showed the most important parameters forgrounddeposits at distances greater than 10 m from the sprayer.deposits at distances greater than 10 m from the sprayer.Those relating to the wider environmentThose relating to the wider environmentboom heightboom heightwind speedwind speed.evaporation rate, and minimum droplet sizeevaporation rate, and minimum droplet sizeThose relating tothe specific nozzleThose relating to the specific nozzledroplet size distributiondroplet size distributionentrained air velocityentrained air velocityEMPM July 27, 201021PlansAdditional input parameters refined for AirAdditional input parameters refined for AirInduction (AI) nozzles to compare to CanadianInduction (AI) nozzles to compare to CanadianWolf and/or Belgium field dataWolf and/or Belgium field dataFurther investigate multiple nozzle effectFurther investigate multiple nozzle effectMay require larger wind tunnel e.g. EPA, RTPMay require larger wind tunnel e.g. EPA, RTPObtain better nozzle/spray input data to matchObtain better nozzle/spray input data to matchSDTF tank mix for refined comparisonsSDTF tank mix for refined comparisonsPossible collaborative CFD model refinementsPossible collaborative CFD model refinementsEMPM July 27, 201022AcknowledgementsAcknowledgementsPaul C.H. Miller, Silsoe Applic. Unit NAIDPaul C.H. Miller, Silsoe Applic. Unit NAID-TAGMark Ledson, Crop Life AmericaMark Ledson, Crop Life AmericaQUESTIONSQUESTIONSRef. ASABE 1009781 A Spray Drift Model for AssessmentRef. ASABE 1009781 A Spray Drift Model for Assessmentof Ground Deposits from Boom Sprayers, (2010) Butlerof Ground Deposits from Boom Sprayers, (2010) ButlerEllis, C.Ellis, C.