AERODYNAMICS AND HEAT EXCHANGE OF SINGLE END TUBE DURING EXTERNAL FLOW

In Ukraine, the safety of modern thermal power plants depends on reliable operation equipment installed them. Unfortunately, technical condition chimneys is not properly maintained. Of course, modernization basic (boilers, switching to another type fuel) leads a decrease in temperature exhaust gases. An important aspect maintain moisture gases.
 feature external flow are large Reynolds numbers Re = wd/n, which reach 106 and more. calculation only average heat transfer coefficient outer surface pipe usually determined, features aerodynamics local due conicity taken into account.
 The work devoted study air single conical chimney. method computer modeling with numerical integration equations motion energy was used research. At first stage, uniform profile considered. Further, influence surrounding infrastructure tube studied.
 vertical 40 m height, 1.7 diameter at base 0.85 mouth for calculation. model calculated ANSYS2020-R1 program. developed homogeneous area environment. order obtain results, conducted optimal set grid parameters conditions. grids that affect distance node from cylinder wall (options a, b, c, d) rate increase size elements as they move away interest (Growth GR) were studied. cylindrical constant has been chosen analyze sensitivity check grid.
 turbulence choosen following: RNG k-ε common tasks this class, Enhanced Wall Function, solution algorithm connection velocity pressure stable flows Simplex. It determined case if between more than 8 mm, instability deviation obtained data values 20% appears. As result research, parameter matching “2d” option table 1 selected, i.e.: GR 1.1, h mm. transfer, conventionally divided 22 sections (with height each). front considered.
 seen, maximum value Zone(21-22). research shows oncoming 25 m/s causes 62.5 W/m2K, 61.1 W/m2K according known formula . This indicates small effect taper entire pipe.
 calculations, three types areas considered: A - open coasts seas, lakes reservoirs, rural areas, including buildings less 10 high; B urban forests other evenly covered obstacles higher m; C dense m. Thus, wind speed profiles different terrain nonlinear.
 (type terrain) significant coefficient. confirms need take account transfer.