DEM(離散要素法)シミュレーションのための各種粒子－流体間相互作用力推算式の検討と粒子間伝熱のモデル化

岡山理科大学201

Heat Generation Inside Turbocharger Without External Heat Source

Recently, many vehicle manufacturers started to invest in new technology to reduce the emission produced by their engines. Due to the emission regulations that become more stringent and the rising demand for highly efficient vehicles, many new technologies were introduced to achieve the demand. One of the technologies that gain popularity in modern vehicles is applying force induction systems such as turbocharging and supercharging the engine. By using the turbocharger, two major advantages can be achieved which are increasing engine efficiency and engine size reduction. However, turbocharger performance will be affected by the amount of heat that is generated due to friction inside the bearing, air compression process and also the heat transfer from the exhaust gas that has high temperature and pressure. In this paper, the heat generation inside the turbocharger unit without any external heat source was measured and analysed. A turbocharger unit from Garrett Turbocharger where the model is GT2056 was used for this experiment. The operating speed in the study is recorded between 20 000 rpm until 70 000 rpm and the temperature at the turbine inlet and compressor inlet is at room temperature. The parameters that were measured are the temperature difference at the turbine side, bearing housing and also compressor side. From the results obtained, it can be concluded that the bearing housing produces a higher amount of heat compared to the compressor side while the turbine side will experience heat loss

NUMERICAL EXPERIMENT ON EFFECT OF SURFACE ROUGHNESS FOR HEAT AND FLOW AROUND TWO CONTACTING PARTICLES

The aim of the present work is to establish a model of heat transfer between particles by using the numerical simulation that can be incorporated in the discrete element method (DEM). The contact heat transfer between particles can be regarded as a contact thermal resistance problem. In the thermal resistance model, the local characteristics, e.g. exact contact area and heat flux distribution on particle surface, are important. However, it is difficult to measure such factors in detail. Accordingly, the authors utilized a numerical simulation. The thermal resistance was modeled by placing a small solid block between the contacting areas in the simulation. The small solid thickness represents the surface roughness and the width represents the contact force. The simulated temperature profile along the center line through two particle’s centers well agreed with measured one

Effects of lean combustion on bioethanol-gasoline blends using turbocharged spark ignition engine

Liquid alternative fuels have been utilised as engine fuel since the 19th century. For several alternative fuels, bioethanol is well-known as the most suited friendly, alternative-product based and renewable for use in spark-ignition (SI) engines. In addition, it is well known that bioethanol has higher evaporation of heat, research octane number and flammability of temperature; therefore, it has a greater influence on performance and lower emission. In this study, the effect of gasoline fuel RON95 (G) was blended into bioethanol fuel (E10, E20 and E30) to investigate the engine combustion, performance and emission. The engine used was 1.8L Mitsubishi, four-cylinder, four-stroke, multipoint port injection and turbocharger SI. The engine speed used was 1000-3000 rpm at 10-40% load with wide-open throttle (WOT). The results showed that bioethanol addition to gasoline increases the brake torque at a higher load. The mass fraction burn (MFB) and coefficient of variation (COV) blend fuel and main fuel are comparable to each other. The brake specific fuel consumption (BSFC) significantly increases when engine speed increases. The emission of nitrogen oxide (NOx), carbon monoxide (CO), and hydrocarbon (HC) emissions reduced dramatically compared to gasoline fuel. Indeed, bioethanol-gasoline fuel allows the engine utilised in low proportion to increase engine performance and lower engine emission

Evaluation of properties on performance and emission to turbocharged SI engine using fusel oil blend with gasoline

Biofuel has the potential to be used as an alternative fuel compared to petroleum gasoline for the purpose increase performance and reducing emissions. The objective of the study is to evaluate performance and emission on properties of 10–30% fusel oil blends with pure gasoline (Ron 95) at 3000 rpm. In this experiment, three fuels were designed from fusel oil to test engine performance and emission. The haltech ECU was an escalation to set ignition, injection timing and injection mass when using fusel oil blends to reach stoichiometric level. In this study, pure gasoline was set as a reference. The experiments were conducted on 1.8L turbocharged 4-cylinder, spark ignition engine, port injection and coupled with 100 kW eddy current dynamometer. During engine testing, the throttle position was applied to 10–40%. As a result, averaged BMEP increase at 11.9%, 17.8% and 21.3% for F10, F20 and F30 respectively compared to gasoline. The VE and BSFC averaged increased 8.3% and 6.17% compared to pure gasoline for 10–40% engine load. The emissions for CO and HC on these observations increased while the NOx decreased when fusel oil blends were utilized. The recommendation used in study is low proportion blends to assess different properties for engine test

Effect of Vaned Diffuser on the Performance of Small Turbocharger

This work presents an experimental investigation of performance of small turbocharger compressor with vaned diffuser. The aim of the study is to investigate the effect of number vaned diffuser on peak pressure ratio in turbocharger. The study was carried out using cold-flow turbocharger test rig driven by compressed air with the impeller rotational speed from 40,000 to 70,000 rpm. Tests were conducted with 6, 8 and 10 number of vanes while maintaining the vane blades angle of 6°, turning angle of 30° and blade length of 21.8 mm. The vanes as a flow deflector were designed as a thin flat plate of 1 mm thickness. All the results were compared with original vaneless diffuser of the compressor. The results found that the proposed design of 6 and 8 vanes shifted the peak pressure ratio toward low mass flow rate region. It was observed that modification from conventional vaneless diffuser compressor to the one equipped with vaned diffuser has significant improvement on the overall pressure ratio of the turbocharger

Wakaf pendidikan tinggi sebagai sumber penjanaan dana dalam kerangka ekonomi Islam di Malaysia / Baterah Alias … [et al.]

Wakaf pendidikan tinggi penting bagi membiayai pendidikan pelajar yang kurang mampu untuk meneruskan pengajian serta membiayai perbelanjaan pengurusan universiti. Pada masa kini, wakaf pendidikan tinggi menjadi topik utama Kementerian Pengajian Tinggi sebagai suatu mekanisme pembiayaan perbelanjaan mengurus universiti tanpa perlu bergantung sepenuhnya kepada pihak kerajaan. Objektif kajian ini ialah untuk menganalisis institusi pendidikan tinggi di Malaysia yang menggunakan wakaf sebagai salah satu mekanisme penjanaan aset untuk menjalankan operasinya dengan mengambil Universiti Islam Malaysia (UIM) sebagai model kajian. Kajian menggunakan metode kajian perpustakaan dan lapangan untuk mendapatkan data primer dan sekunder. Kajian lapangan menggunakan instrument temubual dengan responden yang terlibat secara langsung dengan pengurusan tertinggi Universiti Islam Malaysia (UIM). Dapatan kajian menunjukkan Universiti Islam Malaysia (UIM) berjaya menjadikan wakaf sebagai aset penjanaan pendapatan dalam operasinya bagi melestarikan pendidikan tinggi di Malaysia. UIM menguruskan dana wakaf melalui hasil sewaan, sumbangan daripada Majlis Agama Islam dan badan korporat. Justeru, pelaksanaan wakaf pendidikan tinggi yang dilaksanakan di Universiti Islam Malaysia (UIM) boleh dijadikan sebagai model kepada institusi pendidikan lain dalam usaha membangunkan harta wakaf serta menjana pendapatan demi kelestarian wakaf pendidikan di Malaysia