# Numerical Simulation of Intrachamber Processes in the Power Plant
## 3 Results  
As a result of the calculations, instantaneous fields of physical quantities in the CC PP were obtained. The process of rearranging the flow structure near impermeable surfaces of PP was studied upon changing the geometry of the mass supply channel (Figure 3, black lines). As shown in Figure 3 (black lines), an increase in the mass supply channel causes rearrangement of the flow structure near the nozzle bottom. However, regardless of the position of the mass supply boundaries on the nozzle cover, the formation of a central nodal point is revealed--the stagnation point, four radial flow-out lines coming from the nodal point, and eight peripheral flow-down lines; that is, the topological configuration of flows near the nozzle cover is invariant. At the same time, the rearrangement of the flow structure at the periphery of the cover between nozzles is noted. Thus, the rearrangement of reverse flows that are localized in the inter-nozzle part of the peripheral area of the pre-nozzle volume leads to the transformation of the singular point of the \"unstable knot\" type into a singular point of the \"unstable focus\" type with its subsequent periodic transformation (with the frequency 1 per 0.0003 s) into a singular point of the \"saddle-focus\" type and back into a point of the \"unstable focus\" type, which is associated with the formation of the separated flow near the nozzle entrance. Rearrangement of the flow is accompanied by an increase in the density of heat fluxes in the peripheral area of the PV, while after the formation of the separated zone in the area of the nozzle entrance, stabilization of heat fluxes near the nozzle cover is observed. It should be noted that the change in the geometry of the mass supply channel also affects the structure of the flow near the impermeable end of the channel (Figure 4, black lines). Figure 2: Relative pressure distribution over the nozzle bottom and end surface. Figure 3: Transformation of peripheral structures in the vicinity of the nozzle cover at PP operation: black lines are current lines, color counter is a field of heat transfer coefficient (minimal is a blue color, maximal is a red color), where (**a**) for time 0.0001[s], (**b**) for time 0.0002[s],(**c**) for time 0.0003[s], (**d**) for time 0.0004-0.0005[s], (**e**) for time 0.0006[s] and (**f**) for time 0.0007–0.001[s]. As shown in Figure 4, the movement of the mass supply boundaries leads to a rearrangement of the flow structure near the armored end of the channel. The flow symmetry violation in the inter-slot space is revealed. The central singular point of the \"knot\" type, which is typical for quasi-stationary modes [20], is transformed into a spatial configuration of the singular point of the \"saddle\" type with the subsequent transition to the \"unstable knot\". In this case, the localization of singular points is shifted from the central area of the channel end to the channel periphery. This process is accompanied by a local increase in the intensity of heat fluxes (near singular points) with a decrease in heat flux values, which are integrated across the section. Analysis of the obtained data revealed the dependence of the Nusselt number in the central point of stagnation on the time of the PP operation and compared quasi-stationary sections of the obtained curve with the typical structures of the flow near the cover (Figure 5). It should be noted that the structure of the limiting flow lines near the central nodal point is invariant to the shape of the geometry of the mass supply channel (Figure 3) and varies only slightly with the process time. On the graph of the change in the Nusselt number versus the time (Figure 5), we can distinguish intervals I, II, III and IV with a linear law of change in Nu(t). These intervals are characterized by the invariance of the flow structure (shown in Figure 5).