“Experimental and Theoretical Study of a Multi- Stage Solar Still Connected to Evacuated Solar Collector Tubes”

التقطير الشمسي أحد الحلول الفعالة والمفيدة لحل مشكلة شحة المياه النقية على سطح الارض. استعمل مقطر شمسي متعدد الطبقات وتم تحسين ادائه من خلال ربطه بانابيب مفرغة لتجميع الطاقة الشمسية. فكانت نسبة الزيادة بالانتاجية عن الانواع الاخرى بنسبة (38%). اجريت دراستان عملية ونظرية لحالتان الاولى كانت باحتواء خزانات المقطر الشمسي على الماء فقط من دون اي اضافة اما الحالة الاخرى فكانت باضافة ليف النخل الى حوض المرحلة الاولى. اضافة ليف النخل حسن من الانناجية الليلية للمقطر فكانت نسبة الزيادة في الانتاجية الليلية حوالي (25%) عما هو فارغ. يعتبر هذا النوع من المقطرات الشمسية تقنية حديثة في تحسين اداء المقطرات الشمسية متعددة الطبقات.Solar distillation is an effective and a useful method to solve the problem of water scarcity usable on the surface of the earth. A multi-stage solar still was used, and the performance of it was improved by linking it to (Evacuated Solar Collector Tubes), the rate of increase in productivity is about (38%). Practical and theoretical calculations were carried out on two cases. The first case was the basin of the first stage containing water only; the second case was the basin containing the fiber of the palm. When comparing the two cases there was a similarity between the two cases, but the addition of leaf fiber improved the increase in night productivity. The rate of increase in night productivity is about (25%).This type of solar still was a modern technology in improving the performance of multi-stage solar still

Effect of Orifice Shape and Bore-Area on Noise Attenuation in a Reactive Muffler

IC engines are a major source of noise pollution. Mufflers require specific design and construction. Considering various noise parameters produced by the engine,the conventional design does not include much of a parametric noise analysis or other engine characteristics. In this study, a muffler for internal combustion engine has been designed and manufactured. The performance characteristic and the effect on transmission losses are investigated for different types of orifice plates (circle and Square rectangle, triangle) with different bore areas and frequency. Agood agreement with other works is obtained where the triangular bore shape orifice with minimum bore area is found to be the most effective

Applications of Compound Nanotechnology and Twisted Inserts for Enhanced Heat Transfer

Nanoadditives are a type of heat transfer enhancement techniques adopted in heat exchangers to improve the performance of industrial plants through improvement of the thermal properties of base fluids. Recently, various types of inserts with nanofluids are adopted to enhance the thermal performance of double pipe heat exchangers. In the current article, TiO2/water nanofluid with multiple twisted tape inserts was investigated as a hybrid enhancement technique of heat transfer in straight pipes. The investigations were carried out experimentally and numerically at Reynolds numbers varied from 5000 to 20,000. Using nanofluid with 0.1% TiO2 nanoparticles volume fraction demonstrated enhanced heat transfer with slight increase in pressure drop. Results are showing a maximum increase of 110.8% in Nusselt number in a tube fitted with quintuple twisted tape inserts with 25.2% increase in the pressure drop. However, as the article is representing a part of specified book on heat exchangers, the literature has been extended to provide sufficient background to the reader on the use of nanotech, twisted inserts, and hybrid of compound nanofluids and inserts to enhance heat transfer processes

Experimental Investigation of Coolant Side Characteristic on the Performance of Air-Cooled Condenser Structured by Horizontal Flattened Tube

The steam condensation process has been experimentally investigated in an air-cooled condenser (ACC). The ACC has been designed and built using a flattened cross-section horizontal tube. The flattened tube has an internal dimension of 102 mm x 12 mm with 4030 mm length. A range of vacuum operating conditions are applied to operate the ACC. In the experiments, parameters such as vacuum pressure, saturated temperature, wall tube temperature, rate of heat transfer, and local average steam heat transfer coefficient have been considered along the flow direction with the variation of cooling water temperature. The experimental results revealed that the steam saturated temperature and the related pressure decrease with the reduction of the cooling water temperature, and the temperatures of the upper and lower parts of the horizontal flattened tube. The results also showed that the local steam condensation heat transfer coefficient decreases along with the direction of the flow, but it there is incrementing with the decreasing of saturated steam temperature at a certain range of cooling water temperature