## THERMAL SCIENCE

International Scientific Journal

### AIR FORCED CONVECTION OVER A TWO-SIDED PLATE EXTENDED BY RECTANGULAR HOLLOW BLOCKS

**ABSTRACT**

Our work focuses on an array of hollow blocks formed on a two-sided plate, inserted in a rectangular channel, heated and exposed to forced convection of air at room temperature. The thermal performance of the extended surface of the plates is investigated within a range of air velocities and power input. The investigation is conducted experimentally, using an infrared camera, and numerically in a 3-D computational domain. The experimental results and the numerical calculations showed quantitatively a satisfactory agreement. As expected, the heat transfer rates significantly increased as the air velocity in the channel increased. At low velocities the thermal performance of the extended plate compared to the performance of a flat plate. A numerical analysis of the extensions size and the ratio of plate height to width were also carried out and its effect upon the thermal performance of the system was examined. Relation between fluid pressure losses and heat transfer was studied and generalized. The application of the surfaces extended by blocks is found in several industries, for example in electronic equipment, solar industry, and others.

**KEYWORDS**

PAPER SUBMITTED: 2019-01-12

PAPER REVISED: 2019-02-26

PAPER ACCEPTED: 2019-04-08

PUBLISHED ONLINE: 2019-09-22

**THERMAL SCIENCE** YEAR

**2019**, VOLUME

**23**, ISSUE

**Supplement 4**, PAGES [S1251 - S2160]

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