Total Pressure Loss through a Sudden Expansion

Figure 3.33: Losses through a Sudden Expansion, Borda-Carnot Equation


Consider a sudden expansion placed in a duct (Fig.3.33). The flow does not follow the area changes as suddenly as the geometry does. Any flow will find the sudden area increase difficult to negotiate. In fact a recirculating flow develops as was seen in case of the orifice flow. This gives to losses which are reflected in the total pressure at downstream being reduced. It is possible to calculate this loss from a control volume analysis.


(c) Aerospace, Mechanical & Mechatronic Engg. 2005
University of Sydney