جستجوی مقالات مرتبط با کلیدواژه « plate-fin » در نشریات گروه « مکانیک »

In the present work, the effects of fin pitch, transverse pitch, longitudinal pitch and the number of the longitudinal pitch in a plate-fin flat tube heat exchanger were studied. The fluid flow was assumed laminar, steady, and incompressible. Continuity, momentum, and energy equations for fluid flow and conduction equation for fin were solved, using the finite volume method. Dimensionless results showed that increasing the fin pitch causes to increase of the j-Coulburn coefficient by 132.68% and reduces the friction coefficient rate by 13.35%. Also, increasing transverse tube pitch causes to increase of j coefficient by 203.83% and reduces 24.22% of the f coefficient. By increasing longitudinal tube pitch, j and f coefficients are reduced 84% and 32%, respectively. Dimensional results showed that by increasing fin pitch, heat transfer is reduced 2.2% and thermal performance is increased by 75%. Increasing transverse tube pitch causes to increase heat transfer and thermal performance about 341% and 255%, respectively. Increasing longitudinal tube pitches result in decreasing the heat transfer and thermal performance about 71% and 79%, respectively. Increasing the number of longitudinal tube pitches, N, causes to increase of the heat transfer rate, but for N>28, no sensible increase in heat transfer rate is observed therefore, N>28 is not recommended. Maximum thermal performance is achieved at N=5 and for N>5 thermal performance is decreased.

This article was carried out to investigate and compare fin-tube and plate-fin intercooler at different conditions (non-uniformity of velocity and non-uniformity of temperature of car inlet air with radiator effects) to optimize intercooler layout in cooling system. A tow-dimensional code for fin-tube heat exchangers (fin-tube intercooler and radiator) and a three-dimensional code for plate-fin intercooler were developed by ε-NTU method. Fin-tube model was validated with experimental tunnel test data and plate fin was validated by available data at literature. Results showed that plate-fin performance at least 6.25% better than fin-tube intercooler. Doubling the aspect ratio caused 1.5% and 5% increase of plate-fin and fin-tube intercooler heat transfer respectively. When non-uniformity of velocity increases to 0.8, heat transfer decreases 13.8% and 19.6% for fin-tube and plate-fin intercooler respectively. This reduction in performance is the maximum value that is produced in planting intercooler along the wheels and above the engine. Applying radiator in system and planting block result in approximately 4.5% and 2.4% impairing performance of fin-tube and plate-fin intercooler respectively while changing position of block dose not effect on intercooler performance. The presence of shields and other obstacles in front of the car will create such an impact on the intercooler. Pressure drop of fin-tube intercooler 37.5% lower than plate-fin intercooler.