TY - JOUR AU - . Basher, Hadi O AU - Al-Turaihi, Riyadh S AU - Shubba, Ahmed A. PY - 2020/06/28 Y2 - 2024/03/28 TI - C INVESTIGATION OF HEAT TRANSFER COEFFICIENT AUGMENTATION IN DIVERGENT RECTANGULAR DUCT FOR TWO PHASES FLOW (AIR-WATER) JF - THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING JA - IQJMME VL - 20 IS - 2 SE - Articles DO - 10.32852/iqjfmme.v20i2.492 UR - https://iqjfmme.com/index.php/jmme/article/view/492 SP - 111-121 AB - <p><span class="fontstyle0">In this project, the flow distribution for air and water, and the enhancement of the heat<br>transfer coefficient are experimentally studied. Experimental studies have been performed to<br>test the influence of discharge, pitch, the height of ribs at a constant heat flux on the<br>temperature and pressure distributions. Along the channel of the test and the heat transfer<br>coefficient, the water volume flow rate was about (5-12 L/min), the air volume flow rate was<br>about (5.83-16.66 L/min), and heat were (80, 100,120, watt). An experimental rig was<br>constructed within the test whole system. On the other hands, the channel has a divergent<br>section with an angle =15o with vertical axis. The study included changing in the ribs height<br>by using three values (12, 15, 18 mm) and changing the ribs pitch into three values (5, 8, 10<br>mm).The results indicated an increasing in the local heat transfer coefficient as a result of<br>increasing the discharge. While there was an inverse influence for the temperature distribution<br>along the test channel which drops when the discharge rise. The results also confirm that the<br>increasing in the pitch distance leads to reduce the heat transfer coefficient. Increasing the<br>ribs height increases the coefficient of heat transfer. However, the experiment heat transfer<br>coefficient improves about (15.6 %) when the water volume flow rate increased from (5 to 12<br>L/min), and about (18.7%) when the air volume flow rate increased from (5.83 to 16.66<br>L/min). The best heat transfer coefficient was about (35.6 %) which can be achieved when<br>the pitch decreased from (10 to 5mm). The increasing of the height from (12 to 18) mm<br>improves the heat transfer coefficient about (11.2 %). The best rib dimension was 18 mm<br>height, and 5 mm pitch, which give a maximum heat transfer coefficient (1212.02 W/m2. </span><span class="fontstyle0">o</span><span class="fontstyle0">C).</span> </p> ER -