Skip to main content

Science – Society – Technology

Table 5 Approximation of hydraulic results following the scheme \({c_{\text{opt}}}({\text{SDR}})= \frac{m}{{\text{SDR}}} +b\)

From: Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates

Case Parameters regression
Material \({r_a}\) Slope m intercept b RMSE
   Laminar
0.5604 0.5367 0.0011
   Turbulent
Plastic \(r_{\min}\) 0.5996 0.6093 0.0010
\(r_{m}\) 0.5994 0.6093 0.0010
\(r_{\max}\) 0.5992 0.6093 0.0010
Steel \(r_{\min}\) 0.6068 0.6105 0.0009
\(r_{m}\) 0.6081 0.6118 0.0009
\(r_{\max}\) 0.6099 0.6126 0.0010
Stand. \(r_{\min}\) 0.5954 0.5639 0.0011
\(r_{m}\) 0.5935 0.5770 0.0010
\(r_{\max}\) 0.5927 0.5940 0.0010
Switch \(r_{\min}\) 0.5959 0.6293 0.0009
\(r_{m}\) 0.5997 0.6274 0.0009
\(r_{\max}\) 0.6074 0.6226 0.0009
   Turbulent rough regime
Plastic \(r_{\min}\) 0.6092 0.6191 0.0009
\(r_{m}\) 0.6092 0.6193 0.0009
\(r_{\max}\) 0.6092 0.6198 0.0009
Steel \(r_{\min}\) 0.6064 0.6109 0.0009
\(r_{m}\) 0.6073 0.6126 0.0009
\(r_{\max}\) 0.6082 0.6147 0.0009
Stand. \(r_{\min}\) 0.6407 0.5238 0.0013
\(r_{m}\) 0.6414 0.5321 0.0013
\(r_{\max}\) 0.6412 0.5438 0.0012
Switch \(r_{\min}\) 0.5933 0.6306 0.0009
\(r_{m}\) 0.5950 0.6298 0.0009
\(r_{\max}\) 0.5973 0.6288 0.0009