A generalized friction correlation for louver fin geometry

All correlations by Chang and co-workers and Kim and Bullard can only correlate less than 67% (as low as 36.56%) of the current experimental data with a deviation of ±25%.

“As can be seen from the previously discussed four correlations, all the correlations by Chang and co-works and Kim and Bullard can only correlate less than 67% (as low as 36.56%) of the current experimental data with a deviation of ± 25%.”

The generalized correlations [41, 58, 59, 62] show an excellent agreement with the experimental values reported by Kays and London for the '1/4(b)-11.1' core.

“Practically, these correlations show an excellent agreement with those reported by Kays and London [40], as shown in Figure 6.”

Figure 5 shows that the correlation error differences among studies (Park and Jacobi, Chang and Wang, Chang et al., and Kim and Bullard) were not significant except the errors associated with f-factor introduced by Kim and Bullard.

“However, Figure 5 shows that the correlation error differences among studies (Park and Jacobi [41], Chang and Wang [59], Chang et al. [58], and Kim and Bullard [61]) were not significant except the errors associated with f -factor introduced by Kim and Bullard [61].”

A combination of most previous experimental data (91 cores) for louver-fin were correlated to introduce new j and f factor correlations for all louvered fin constructions.

“A combination of most previous experimental data (91 cores) for louver-fin were correlated to introduce new jand ffactor correlations for all louvered fin constructions [58, 59].”

Chang and Wang and Chang et al. introduced air-side f- and j-factor correlations for all types of louvered fin heat exchangers using 91 different designs, including those of previous experimental data.

“Amongst the correlations listed in Table 1, Chang and Wang [59] and Chang et al. [58] introduced air-side f - and j -factor correlations for all types of louvered fin heat exchangers using 91 different designs, including those of previous experimental data [48, 53, 55, 57-59, 68-70].”

With error of ±15%, Chang and Wang and Chang et al. included more than 90% of the experimental data to obtain both j- and f-factor correlations, whereas the other previous works included less than 70% of the total available experimental data.

“For example, with error of ±15%, Chang and Wang [59] and Chang et al. [58] included more than 90% of the experimental data to obtain both j - and f -factor correlations, whereas the other previous works included less than 70% of the total available experimental data, this is also shown in Figure 4.”

The j- and f-factor correlations [58, 59] are valid over a wide range of geometries; for example, FPI = 4 - 49.

“Valid over a wide range of geometries; for example, FPI = 4 - 49.”

The number of geometries tested to obtain the j- and f-factor correlations [58, 59] is 91.

“No. of geometries tested to obtain the correlations is 91.”

Generalized j- and f-factor correlations exist for all types of louvered fin heat exchangers [58, 59].

“Generalized j - and f -factor correlations for all types of louvered fin heat exchangers.”

Some researchers introduced generalized correlations such as those obtained by [41, 58, 59, 62] for representing all types of louver-fin arrangements.

“Some researchers introduced generalized correlations such as those obtained by [41, 58, 59, 62] for representing all types of louver-fin arrangements.”