ABSTRACT
DrJolly:DrCookementionedthatifyouclosedowntheairgapallowingentryof airtothefireyougetasignificantincreaseintimeoffireatamodestreductionin temperature.Isthereanoptimumopeningwhichgivesyouthemaximumtotalenergyin thefireandwouldthatbeaworsecasethanthenormalprogressionwhichIbelieveat Cardingtonhasbeentoessentiallysmashthewindowsopen? DrCooke:Intermsofthepeaktemperatureswhichmayoperateforaslightlyshorter lengthoftime,yougetthisconditionwhentheventilationopeninginthefrontwallis aboutaquarterofthetotalopening.Ifyouarelookingatasteelstructure,thatiswhatyou areafter.Ihavenotconvertedthatintowhatmegawattsareproduced,butifyoulookat theequationwhichrelatestherateofburningtotheheightoftheopening,whatyoufind isthatthemaximumrateofburningwhichwouldprovideyouwiththemaximumrateof powerproduction,isagainwhereyouhaveaventilationopeningroughlyequaltoone quarterofthefrontwall.Itdependsupontheshapeofthecompartment,ofcourse.Most peoplearesurprisedthatasyoureducetheventilation,youincreasethepunishmentonthe structure.Ifyouthinkofitintermsofyouarereleasinglessoftheradiationfromthe frontofthecompartmentbecauseyouhavenowgotawallcoveringupmostoftheflame, andyouarelockinginheatinthestructureforalongerperiod,thenmakesmoresensethat whateverisintheregetsmorestructuralpunishment.
