Influence of Tool Geometry on Surface Roughness and Tool Wear When Turning AISI 304L Using Taguchi Optimisation Methodology

المجلة: International Journal of Mechanical and Industrial Engineering

سنة النشر: 2023

تاريخ النشر: 2023-01-11

This paper presents an experimental optimisation of surface roughness (Ra) and tool wear in the precision turning of AISI 304L alloy using a wiper and conventional cutting tools under wet cutting conditions. The machining trials were conducted based on Taguchi methodology employing an L9 orthogonal array design with four process parameters: feed rate, spindle speed, depth of cut, and cutting tool type. The experimental results were utilised to characterise the main factors affecting Ra and tool wear using the analyses of means (AOM) and variance (ANOVA). The results show that the wiper tools outperformed conventional tools in terms of surface quality and tool wear at optimal cutting conditions. The ANOVA results indicate that the main factors contributing to lower Ra are cutting tool type and feed rate, with percentage contribution ratios (PCRs) of 58.69% and 25.18% respectively. This confirms that tool type is the most significant factor affecting surface quality when turning AISI 304L. Additionally, a substantial reduction in tool wear was observed when a wiper insert was used, whereas noticeable increases in tool wear occurred when higher cutting speeds were employed for both tool types. These trends confirm the ANOVA outcomes that cutting speed has a significant effect on tool wear, with a PCR value of 39.22%, followed by tool type with a PCR of 27.40%. All machining trials generated similar continuous spiral or curl-shaped chips. A noticeable difference was found in the radius of the produced curl-shaped chips at different cutting speeds when turning AISI 304L under wet cutting conditions.

Comparison of Fuel Saving For Air by Chiller at The Entrance to The Gas Turbine Between Two Areas in Libya

المجلة: مجلة ليبيا للعلوم التطبيقية والتقنية

سنة النشر: 2023

تاريخ النشر: 2023-01-12

This paper prepares the analysis of gas turbine (GT) and generator analysis as a basis for the climatic position of the power sector between two different Libyan cities, Tripoli in the north and Hon in the south Libya. It is therefore a system characterized by high intake air temperatures and reduced energy efficiency, requiring intake cooling air. Lithium bromide absorption coolers reduce gas turbine inlet air temperatures by up to 15°C and water-ammonia absorption coolers and refrigerant spray with air temperature reductions of up to 10°C and little use of heat from the turbine's exhaust gases are considered waste heat. Heat transformer. Fuel savings by cooling gas turbine inlet air to different temperatures using different types of heat converters have been evaluated in regions of Libya where electricity production is concentrated in generators. turbine. The gas turbine inlet cooling air reaches temperatures of up to 10 and 7°C via refrigerant injection coolers and water-ammonia absorption which have been shown to deliver annular fuel savings greater than 1, 3 to 1.5 times that of a lithium bromide absorption cooler supplying gas turbine inlet. Air temperature drops to 15 ° С. As a result, higher efficiency of deep cooling of gas turbine intake air to temperatures of 10 and 7°C through water-ammonia absorption and refrigerant injection coolers has been demonstrated. The possibility of annular fuel savings due to air cooling at the inlet of gas turbine generators using different types of thermal converters was evaluated for Libyan regions where electricity production is concentrated.

تأث ر يرالزعانفرعلىرخلطرالهواءر ر فرمنظومةرالتكييفر

المجلة: مجلة ليبيا للعلوم التطبيقية والتقنية

سنة النشر: 2021

تاريخ النشر: 2021-01-12

من اهم المكونات ف ي أنظمة التدفئة والتهوية وتكييف الهواء ) HVAC ( هي وحدة استلام الهواء ) AHU (، حيث يتم توفير الهواء من خلال مروحة إمداد إلى وحدة استلام الهواء ) AHU (، بحيث تستقبل هذه الوحدة الهواء من الخارج ) OA ( من خارج المبنى والهواء العائد ) RA ( من المساحة الداخلية ثم يتم خلط الهواء الخارجي والهواء العائد في وحدة الخلط، ثم يتم تنقيته وتسخينه أو تبريده، وبعد ذلك يتم تسليمه إلى المساحة المراد تكييفها عبر القنوات. يحدث تقسيم طبقي للهواء العائد وتيارات الهواء الخارجية عندما يكون للتيارين اختلاط ضعيف، تنتج هذه المشكلة جزئيًا عن ا نخفاض القوة الدافعة والاضطراب اللذين يعززان الخلط بشكل كبير مع انخفاض السرعات في صندوق الخلط. لسوء الحظ عندما يصبح الهواء الداخل مقسمًا إلى طبقات أو ينفصل إلى طبقات ذات درجات حرارة مختلفة ستحدث العديد من المشكلات في أنظمة HVAC . الغرض من هذه الورقة ه ي البحث في تأثير اضافة زعانف لحجرة الخلط التي تعاني من مشكلة عدم الخلط الجيد للهواء الراجع مع الهواء الخارجي، والعوامل التي تم التركيز عليها هو تأثير تغيير زاوية وحجم الزعنفة على معاملات الخلط، واستخدم لهذا الغرض برنامج الحاسب الالي (Fluent) لمحاكاة المشكلة . ال نتيجة المتحصل عليها، ان اضافة الزعانف الى حجرة الخلط يحسن من عملية الخلط عند اطوال وزوايا مختلفة للزعانف كذلك يزيد من انخفاض الضغط للنظام، وبناءا على كمية الخلط المطلوبة حجم حجرة الخلط المتاحة الحالة ذات افضل خلط مع اقل انخفاض ف ي الضغط يتم اختيارها.

Effect of steam injection in Intercooling and Heat Regenerative Gas Turbine cycle IHSTIG

المجلة: مجلة ليبيا للعلوم التطبيقية والتقنية

سنة النشر: 2021

تاريخ النشر: 2021-01-09

It is known that the efficiency of gas turbines is low, especially when operating in harsh conditions such as high air temperature. Therefore, the performance of gas turbines has been improved by intercooling and heat regenerative. In this work, the possibility of improving efficiency and production capacity was studied by injecting steam into the combustion chamber of a gas turbine, in the presence of intercooling and heat regenerative, the cooling process is carried out by pumping water to cool the compressor, so that it turns into steam, which is then injected into the combustion chamber after passing through a heat recovery steam generator HRSG. The focus has been on the study of the change in the ratio of water to air, as well as the amount of intercooling. The results showed that there is a possibility to raise the efficiency and production capacity at a high water-air ratio, the temperature of the combustion gases has decreased, which helps the turbine blades to withstand, and the production of nitrogen oxides polluting the environment has decreased.