Maha Ali - Academia.edu (original) (raw)

Papers by Maha Ali

Case Studies in Thermal Engineering, 2022

Applied and Computational Mechanics, 2020

Heat sinks are used in industrial equipment to dissipate the excess heat from their heat-generati... more Heat sinks are used in industrial equipment to dissipate the excess heat from their heat-generating parts to the ambient. In the last few years, efforts on manufacturing electronic or mechanical devices with less weight, space, and lower cost were spent. Heat dissipation from the heat sink is stalling a big problem which many researchers are trying to solve. The aim of this study is to brief the previous investigation attempted enhancing the heat sinks thermal performance and to provide help to understand the cooling ability of their specific geometries. The various enhancement techniques used for optimizing the hydrothermal design of a pin fin, flat fin, micro-channel, and topology optimized heat sinks were summarized. The way in which the heat sinks’ thermal performance is affected by orientation, shapes, perforation, slot, interruption, and space between fins and their arrangement under free and forced convection condition also reviewed.

Arabian Journal for Science and Engineering, 2021

The heat transfer performance of the air–water double pipe heat exchanger (HE) was experimentally... more The heat transfer performance of the air–water double pipe heat exchanger (HE) was experimentally investigated. Segmental baffles with semi-circular perforations were introduced in the annular side of HE. Each baffle contains semi-circular fins. Air was used as a working fluid in the annular while, water for the inner tube. Seven different air Reynold’s numbers range from 2700 to 4000 were selected. While water side Reynold’s number fixed at 34,159. Three different semi-circular perforation diameters were studied (30, 25, and 20 mm) to investigate their effect on HE thermal performance. The Nu number, overall heat transfer coefficient, friction factor, and thermal performance factor (TPF) were calculated. Also, compassion for the baffled and un-baffled pipe was done. It was observed that the thermal performance of the baffled pipe HE was better than the un-baffled one. The average overall heat transfer coefficient increases by 29.7%, 62%, and 80.6% by using perforated baffles with 3...

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING, 2018

An experimental study was done to investigate the effect of fin geometrymodification and material... more An experimental study was done to investigate the effect of fin geometrymodification and material type on heat dissipation from a heat sink under natural convection.v-corrugated solid fin and v-corrugated perforated fin were designed for this purpose.Aluminum and Copper metals were selected in designing the fins because their wideapplication in cooling and heating equipment. Three different voltages 110, 150 and 200 Vsupplied to the heat sink to study their effects on the fins performance. Each experimentrepeats two times to reduce the error and the data recorded after reaching the steady stateconditions. The utilization of solid and perforated v-corrugated fins is compared. The resultsshowed that perforated fins dissipated heat more than corresponding solid by 15.4, 34 and32% for aluminum, and 2.7, 2.1 and 4.3% for copper fin in the three voltages. Also, theresults indicated that the heat loss by solid copper fin is greater by 56, 72 and 92% thancorresponding solid aluminum fin and...

Journal of Engineering, 2018

An experimental investigation has been made to study the influence of using v-corrugated aluminum... more An experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching the steady state conditions. The results showed that the v-corrugated fin dissipate heat twice and triple times than flat plate mentioned in past research with the same dimension. Also, the inline perforated fin gave higher enhancement percentage than solid one by 15,...

Applied Thermal Engineering, 2017

Abstract An experimental investigation was made to study the performance of a double pipe heat ex... more Abstract An experimental investigation was made to study the performance of a double pipe heat exchanger, with a triangular copper fins, which is used to extend the outside surface area of the tube. While, an external type of enhancement is used for the inside of the tube by using twisted tapes with various twisted ratio inserts inside the tube. Results for ninety experiments were indicated. These runs were done for plain tube, finned tube and finned tube with twisted tape at three different twisting ratios. Experiments were performed at various Reynolds number for the above profiles both in the inner and outer tube. The results showed that the overall heat transfer coefficient rate for only a finned pipe is (3 times) greater than plane pipe. Furthermore, as the twisted tape ratio used in the inner pipe at (7, 5, 3), the heat transfer rate was increases 4, 6, 8 times the case of plain pipe, respectively. Conversely, the pressure drop and friction factor increase across the inner tube with the decreasing of the twisted tape ratio increasing. The measured and calculated results show the most effective heat exchanger among cases studied in this which is the finned tube with twisted tape at ratio 3.

Case Studies in Thermal Engineering, 2022

Applied and Computational Mechanics, 2020

Heat sinks are used in industrial equipment to dissipate the excess heat from their heat-generati... more Heat sinks are used in industrial equipment to dissipate the excess heat from their heat-generating parts to the ambient. In the last few years, efforts on manufacturing electronic or mechanical devices with less weight, space, and lower cost were spent. Heat dissipation from the heat sink is stalling a big problem which many researchers are trying to solve. The aim of this study is to brief the previous investigation attempted enhancing the heat sinks thermal performance and to provide help to understand the cooling ability of their specific geometries. The various enhancement techniques used for optimizing the hydrothermal design of a pin fin, flat fin, micro-channel, and topology optimized heat sinks were summarized. The way in which the heat sinks’ thermal performance is affected by orientation, shapes, perforation, slot, interruption, and space between fins and their arrangement under free and forced convection condition also reviewed.

Arabian Journal for Science and Engineering, 2021

The heat transfer performance of the air–water double pipe heat exchanger (HE) was experimentally... more The heat transfer performance of the air–water double pipe heat exchanger (HE) was experimentally investigated. Segmental baffles with semi-circular perforations were introduced in the annular side of HE. Each baffle contains semi-circular fins. Air was used as a working fluid in the annular while, water for the inner tube. Seven different air Reynold’s numbers range from 2700 to 4000 were selected. While water side Reynold’s number fixed at 34,159. Three different semi-circular perforation diameters were studied (30, 25, and 20 mm) to investigate their effect on HE thermal performance. The Nu number, overall heat transfer coefficient, friction factor, and thermal performance factor (TPF) were calculated. Also, compassion for the baffled and un-baffled pipe was done. It was observed that the thermal performance of the baffled pipe HE was better than the un-baffled one. The average overall heat transfer coefficient increases by 29.7%, 62%, and 80.6% by using perforated baffles with 3...

THE IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING, 2018

An experimental study was done to investigate the effect of fin geometrymodification and material... more An experimental study was done to investigate the effect of fin geometrymodification and material type on heat dissipation from a heat sink under natural convection.v-corrugated solid fin and v-corrugated perforated fin were designed for this purpose.Aluminum and Copper metals were selected in designing the fins because their wideapplication in cooling and heating equipment. Three different voltages 110, 150 and 200 Vsupplied to the heat sink to study their effects on the fins performance. Each experimentrepeats two times to reduce the error and the data recorded after reaching the steady stateconditions. The utilization of solid and perforated v-corrugated fins is compared. The resultsshowed that perforated fins dissipated heat more than corresponding solid by 15.4, 34 and32% for aluminum, and 2.7, 2.1 and 4.3% for copper fin in the three voltages. Also, theresults indicated that the heat loss by solid copper fin is greater by 56, 72 and 92% thancorresponding solid aluminum fin and...

Journal of Engineering, 2018

An experimental investigation has been made to study the influence of using v-corrugated aluminum... more An experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching the steady state conditions. The results showed that the v-corrugated fin dissipate heat twice and triple times than flat plate mentioned in past research with the same dimension. Also, the inline perforated fin gave higher enhancement percentage than solid one by 15,...

Applied Thermal Engineering, 2017

Abstract An experimental investigation was made to study the performance of a double pipe heat ex... more Abstract An experimental investigation was made to study the performance of a double pipe heat exchanger, with a triangular copper fins, which is used to extend the outside surface area of the tube. While, an external type of enhancement is used for the inside of the tube by using twisted tapes with various twisted ratio inserts inside the tube. Results for ninety experiments were indicated. These runs were done for plain tube, finned tube and finned tube with twisted tape at three different twisting ratios. Experiments were performed at various Reynolds number for the above profiles both in the inner and outer tube. The results showed that the overall heat transfer coefficient rate for only a finned pipe is (3 times) greater than plane pipe. Furthermore, as the twisted tape ratio used in the inner pipe at (7, 5, 3), the heat transfer rate was increases 4, 6, 8 times the case of plain pipe, respectively. Conversely, the pressure drop and friction factor increase across the inner tube with the decreasing of the twisted tape ratio increasing. The measured and calculated results show the most effective heat exchanger among cases studied in this which is the finned tube with twisted tape at ratio 3.