Page 438 - konishipaper

SixthInternational砂mposiumonScaleModeling(ISM-6) Kauai，Hawai，September13-16，2009
Scalemodelingofair-dropedwaterforaerialfirefightingagainsturbanfire
HironoriKikugawaa，*，TadashiKonishia，KeitaHiranob
aDepartmentofMechanicalEng・，OitaNationalColegeofTechnology，Mαki1666，Oita，Japan U AdvancedCourseStudent，OitaNationalColegeofTechnology，Maki・1666，Oita，~αrpan
E-mailadres:kikugavω@oita-ct.acjp
Abstract
Incaseofagreatearthquakedisaster，wideareaurbanfirewouldbeexpandedforlackof firefightingwatersuply企omroaddestruction，hydrantdamageandsoon.Ifairplanes，suchasa helicopter，canbeusedunderspecificconditions，itwouldbeefectiveforfirefighting.Airplanes canariveatthefiresiteinashorttime，andfirefightingcanbecariedoutquickly.Forthis reason，itwouldbeexpectedforaerialfirefightingbyafire-fightinghelicopterforurbanfirein case of a great disaster. However， about the fire extinguish or deter rent ef fect by aerial firefighting，thereisnoenoughresearchworkforurbanfire.Untilnow，therealscaleexperiment usedbyrealhelicopterwascariedoutthretimesbyNationalResearchInstituteoffireand disaster.Itisdificulttocaryouttherealscaleexperimentfrequently.Therefore，inthisresearch， smalmodelexperimentwasproposedandsimilaritywitharealscaleexperimentwasverified. Asaresultofthisresearch，itwasreproducibleabouttheairspreadphenomenonwhichwas dropedwaterfromthebucket.Furthermore，itwasreproducibleabouttheimpactofcrashed waterontheground.
Introduction
OnJanuary1ihin195，amajorearthquakehitthesouthernpartofHyogoPrefectureinJapan. TheeaJihquakewouldcometobeknownasthe"GreatHanshin-Aw司iEarthquake."Inthisgreat earthquake，manybuildings，bridges，androadswereseriouslydamagedandheavycasualties werereported.Justaftertheearthquake，the五rebrokeoutinsimultaneouslyandfrequently，each firewasexpanded，anddamageswereincreased.Atthetimeofgreatdisaster，afirefighting teamisdificulttoariveatthefiresitebydamagesofroadsorbridges.Inadition，hydrants couldnotworkbywaterpipebreakage. Onsuchuniqueconditions，ithasahopeforthe posibilityofaerialfirefightingbyahelicoptertourbanareafire.However，theamountofwater conveyanceatoncebyhelicopterisrestricted，andthereisalimitinthefire-extinguishingefect. Withurbanareafire，itisdificulttoextinguishalthefiretobummanyhousesforlarge combustionareafromaerialfirefightingbyhelicopter.Therefore，waterwasnotsprinkledtoa combustionzonedirectly，butwaterwassprinkledtothesuroundingzone，andaposibilityof controlingafirebysmalamountofwaterwasexamined.Inadition，bydropingwaterfrom theair，itisanxiousaboutthedangerofthehumanlifeconfinedinthecolapsedhousebywater lmpact.
From 197 to 19，National Research Institute ofFire and Disaster (NRIFD) in Japan conductedtherealscaleexperimentusedbyrealhelicopter.In197，preventionefectoffire spreadtodropthewaterinsuroundinghousewasexamined[1].In198，thecasewhereaerial firefightingwasstartedatear1ystageforonlyonebuildingfirewasexamined[2].Sincethis