الفهرس 
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Abstract
-brThis work is established for a heat transfer enhancement through a new design of coils that affect through which enhancement may be achieved.
A new coil design which has chosen in this study is called a spiral coil. Very little researchers focused on this type, so the main idea focused on investigates the thermo-fluid characteristics of these types of coils.
In the present study, the performance of spirally coiled finned tube in cross flow was experimentally investigated. This investigation covers the effects of key design parameters such as curvature ratio, flow direction, air velocity, fin pitch, and chilled water mass flow rate on the performance characteristics of spirally coiled finned tube in cross flow. The purpose is to evaluate this type of spirally finned tube cooling coils with particular reference to bare tube.
The experimental set-up consists of spirally coiled tube which is fabricated by bending a 8.0 mm inside diameter of a straight copper tube into a spiral-coil of five turns. Six test specimens were designed and manufactured with curvature ratios of 0.027, 0.03, 0.04, tube pitches of 18, 20, 30 mm, and fin pitches of 11, 22, 33 mm corresponding to a central angle of (10°, 20° and 30°) respectively .
The runs are carried out in visible test section as a part of suction draft wind tunnel with air Reynolds number ranging from (35500 to 245000) corresponding to air velocity of (1.40 to 9.60 m/s). Two types of chilled water flow directions entering the spiral coil are tested at Reynolds number ranging from (5700 to 25300) corresponding to a water velocity of (0.991 to 2.79 m/s) respectively, the first is innermost flow direction and the other is to outermost flow direction.a heat transfer enhancement through a new design of coils that affect through which enhancement may be achieved.
A new coil design which has chosen in this study is called a spiral coil. Very little researchers focused on this type, so the main idea focused on investigates the thermo-fluid characteristics of these types of coils.
In the present study, the performance of spirally coiled finned tube in cross flow was experimentally investigated. This investigation covers the effects of key design parameters such as curvature ratio, flow direction, air velocity, fin pitch, and chilled water mass flow rate on the performance characteristics of spirally coiled finned tube in cross flow. The purpose is to evaluate this type of spirally finned tube cooling coils with particular reference to bare tube.
The experimental set-up consists of spirally coiled tube which is fabricated by bending a 8.0 mm inside diameter of a straight copper tube into a spiral-coil of five turns. Six test specimens were designed and manufactured with curvature ratios of 0.027, 0.03, 0.04, tube pitches of 18, 20, 30 mm, and fin pitches of 11, 22, 33 mm corresponding to a central angle of (10°, 20° and 30°) respectively .
The runs are carried out in visible test section as a part of suction draft wind tunnel with air Reynolds number ranging from (35500 to 245000) corresponding to air velocity of (1.40 to 9.60 m/s). Two types of chilled water flow directions entering the spiral coil are tested at Reynolds number ranging from (5700 to 25300) corresponding to a water velocity of (0.991 to 2.79 m/s) respectively, the first is innermost flow direction and the other is to outermost flow direction.