Contraction losses

Determine expansion or contraction losses, if any, including tank or vessel entrance or exit losses from Figures 2-12A, 2-15, or 2-16. Convert units to psi, head loss in feet times 0.4331 = psi (for water), or adjust for Sp Gr of other liquids. 

No expansion or contraction losses (except control valve). 

Determine expansion and contraction losses, fittings and at vessel connections. 

The expression non-liquidated damage means actual losses, which are incurred by a client, and could be claimed in the absence of an agreement to a specific amount in the contract. Loss and/or expense can be suffered by a contractor due to other parties who caused him to be delayed. These sums per week are invariably far in excess of any liquidated damages amount set in the contract. 

Geiger, G. E., 1964, Sudden Contraction Losses in Single and Two-Phase Flow, Ph.D. thesis, University of Pittsburgh, Pittsburgh, PA. (3)... 

The loss coefficient is seen to be a function only of the geometry of the system (note that the assumption of plug flow implies that the flow is highly turbulent). For most systems (i.e., flow in valves, fittings, etc.), the loss coefficient cannot be determined accurately from simple theoretical concepts (as in this case) but must be determined empirically. For example, the friction loss in a sudden contraction cannot be calculated by this simple method due to the occurrence of the vena contracta just downstream of the contraction (see Table 7-5 in Chapter 7 and the discussion in Section IV of Chapter 10). For a sharp 90° contraction, the contraction loss coefficient is given by... 

The cyclone in Fig. 22 will have a greater contraction loss than that in Fig. 20 ... 

As would be expected from equation 3.52, expansion and contraction losses for turbulent flow of power law fluids are similar to those for turbulent flow of Newtonian fluids. 

The correlation presented in Fig. 12-6 was developed by Leibson et al.12 on the basis of a formula for C0 obtained by adding the contraction loss from point i to point o of Fig. PI2-1 to the expansion loss from point o to point d. Equations for the contraction loss APJpL and the expansion loss APe/p, are available in standard texts and handbooks on fluid flow. The expressions used are as follows... 

MINIMIZING EXPANSION AND CONTRACTION LOSSES. A contraction loss can be nearly eliminated by reducing the cross section gradually rather than suddenly. For example, if the reduction in cross section shown in Fig. 5.14 is obtained by a conical reducer or by a trumpet-shaped entrance to the smaller pipe, the contraction coefficient can be reduced to approximately 0.05 for all values of SJSa- Separation and vena-contracta formation do not occur unless the decrease in cross section is sudden. 

Contraction-loss coefficient, dimensionless Expansion-loss coefficient, dimensionless Loss factor for fitting or valve, dimensionless Flow consistency index, kg/m-s -" or lb/ft-s " ... 

Kc Contraction loss coefficient for flow at heat exchanger entrance (Eq. 17.65 and... 

Sudden contraction losses. When the cross section of the pipe is suddenly reduced, the stream cannot follow around the sharp corner, and additional frictional losses due to eddies occur. For turbulent flow, this is given by... 

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