Numerical Simulation Of Discharge Capacity Of Ordinary Cast Iron Double Pipe Drainage System

drainage syste m is an important auxiliary equip ment for build ing. It re lates to theuse of architectura l features and qua lity of people’s life.This subject researchescurrent situation and develop ment trend of the research at home and abroad, thenestablis hes two sets of cast iron double pipe model,one syste m is connected with theH tube on each floor,another syste m is connected with the H tube at intervals of onefloor.After testing the drainage capacity and n umerical s imulation with FLUENTsoftware,the following five aspects were discussed in this paper by us ing the met hodof combination of theory and practice.Through the experime nta l and simulated data and the simulated pressure nephog-ram of the pipe at each floor,there is a theory that cast iron doub le pipe syste m has po-sitive and negative pressure in the height of partition and dynamic zero,usually uppernegative and lower positive.The maximum drainage capacity which obtained from numerical simulation oftwo syste ms was cons istent wit h the conc lus ions fro m experime ntal data analys is.Lar-gest water flows about two sets of system are respectively6.0l/s,8.0l/s.Application ofnumerical simulation with FLUENT is reliable in building drainage system.45°elbow is part of a45degree oblique three component,its radius of curvaturehas clear influence on the region near the vortex phenomenon in cast iron double pipedrainage system.Although the large curvature radius can reduce the range effectivelywhich affected by the eddy current and turbule nt kinetic energy etc,it increases the le-ngth of the elbow in the horizonta l direction and the he ight in the vertica l direction,sothat the elbow will be limited in construction.In the largest draina ge flow range of Cast iron doub le pipe draina ge system for a-rchitecture,the bottom me mber (large curvature bend) has a great influence on the pre-ssure fluctuation of the system, There is a great improvement on the positive pressureof the following layers,and even negative pressure appears in the riser area betweenthe bottom horizontal drainage pipe and the first H pipe.Taking the second system as an examp le,when H pipe is mo ved to the185mm ab-ove horizontal branch,this topic finds that H pipe’s connection mode can make a bigdifference to pressure distribution within the system.H pipe above horizontal branchis good for positive pressure,on the contrary H pioe below horizonta l branch contribu-tes to negative pressure.