Pengaruh Isolator Terhadap Kinerja Tungku Gasifikasi Tipe Downdraft

Gasification process is one of the utilization of biomass energy is to convert the energy from the solid materials (biomass) a syn-gas (gas fuel) with limited air supply, which later can be used as fuel. There are several types of gasification is one type of downdraft gasification stove which means the direction of the air flow and gas gasification results clockwise is down. Efforts to optimize the process of gasification one only can be done by adding the isolator on gasification stove. In this research, variations isolator materials used is the pollen bricks, pollen among stones and sand. With the coat the surface of the furnace gasification, will reduce the secretion of the heat insulation on the surface of the furnace. This research aims to find out the influence of the isolator to temperature burning, and the influence of the isolator to the time a flame effective gasification stove with fuel rice chaff. The results of this study found that the average temperature flame effectiveness on a brick powder 563,9°C with temperature isolator 103,6°C and a flame effective 54 minutes. On the pollen among the average temperature flame effective 540,8°C with temperature isolator 135,8°C and a flame effective 52 minutes. While the average temperature sand flame effective 514,62°C and temperatures isolator 147,7°C and a flame effective 50 minutes

Studi Winglet Naca 2409 Menggunakan Computational Fluid Dynamic (CFD)

Di masa lalu penelitian untuk mengetahui peforma suatu benda aerodinamika harus melalui simulasi wind tunnel. Dalam hal ini pengujian menggunakan wind tunnel dari segi akurasi, seksi uji, dan biaya kurang efektif. Oleh sebab itu pada perkembangan teknologi guna memperoleh efektifitas dan akurasi hasil, seksi uji, serta biaya dikembangkan softwere pengganti simulasi wind tunnel, Softwere itu antara lain Ansys, SolidWork, dsb. Tujuan penelitian ini adalah mengetahui optimal winglet, hubungan antara ketinggian penerbangan terhadap performa coefisient lift (CL) dan coefisient drag (CD), distribusi tekanan sertakecepatan pada winglet. Dalam studi penelitian ini dijelaskan hubungan kinerja winglet NACA 2409 pada ketinggian penerbangan 2 km, 4 km, 6 km, 8 km, 10 km, 12 km, 14 km, 16 km, 18 km, 20 km, 24 km, 28 km, 30 km, 32 km terutama hubungan CL dan CD secara komputasi. Percobaan diawali dengan pembuatan model winglet menggunakan SolidWorks, setelah itu meshing dan proses perhitungan yang dilakukan software Ansys-CFD. Analisa meliputi distribusi tekanan dan kecepatan. Hasil penilitian menujukan bahwa kenaikan ketinggian penerbangan dikuti perubahan beberapa hal. Hal tersebut adalah tekanan, suhu, densitas, serta gaya angkat dan gaya hambat. hasil yang diperoleh yang tertinggi pada ketinggian 20 km dengan presurre 5529 Pa, densitas 0,0889 kg.m-3, suhu 216,6 K mendapatkan koefisien lift ( CL ) sebesar 0,921626346 serta koefisien Drag ( CD ) sebesar 0,053 . Hasil terendah pada ketinggian 32 km dengan pressure 889 Pa, densitas 0,0889 kg.m-3, suhu 228,5 K mendapatkan koefisien lift ( CL ) sebesar 0,5266 serta koefisien Drag ( CD ) sebesar 0,0385

Variasi Jumlah Koil Dengan 2 Busi Terhadap Peforma Yamaha Jupiter Z 110 CC

Both spark plugs and coils are important component in the ignition ssystem that will affect performance of the motorcycle combustion engine. This study will reveal the effect of the coils number with two spark plugs on the performance of the internal combustion engine with single cylinder four stroke through experimental testing. Performance parameters measured by the combustion engine torque, power, and specific fuel consumption. This research begins with modifying the internal combustion cylinder head into two holes of spark plug. A dynotets set was used in the experimental in order of test both torque and power. Specific fuel consumption data were obtained with several measuring tools such as burrettes, stopwatch, and tachometer. Both calculated variations data of single coil and two coils are compared to standard design. The result show that the standard ignition produces that the highest torque of 7,21 Nm with the fuel consumption up to 0,105 kg/Hp.h

Studi Efek Semprotan Serangkaian Nosel Pada Cerobong Terhadap Profil Kecepatan Dan Temperatur Dengan Metode CFD

The decrease of temperature in the evaporation chimney could be achieved by adding water spray system inside the chimney. This paper describes a simulation research in order to investigate the influence of the nozzle configuration and the level of humidity to the velocity profile and temperature distribution inside the chimney. This research was performed computationally by applying k-ε turbulence model. Geometry of chimney and nozzle used by other researcher in the previous simulation, including their finding data, were chosen as a standard design during mesh refinement study and validation stage, hereinafter was modified in terms of nozzle configurations inside the chimney. The profile of velocity and temperature were observed along the investigation. The results show that the validation data is consistent to the previous study. The configuration, with 8 nozzles at a height of 3.94 m and 4 nozzles at a height of 3.5 m from the base of the stack, produces an optimum level in terms of the decrease of temperature and the velocity of vapour

Studi CFD Aliran Udara Di Sekeliling WING NACA0015 Yang Dilengkapi Split Flap

The values of lift and drag coefficients of airfoil which is formed by Wing NACA0015 can be obtained through numerical approach, for example by using CFX. The objectives of this study are to simulate and to get the optimum angle of deflection flap and angle of attack and to describe the lift coefficient (CL) and the drag coefficient (CL) in various speed and temperature. This study is to explain the work of wing NACA0015 that operates when take off and landing process only. At the time the speed is relative low. The fist step is to build a model of Wing NACA0015 using solidwork. After that the meshing process was carried out using Ansys CFD software. Those processes resulted parameter, that are : lift coefficient, drag coefficient, distribution of speed and the pressure that accur. The result of this study shows that in the take off and landing process the optimum deflection flap is on 20o and the optimum angle of attack is on 8o. The study also found the highest lift coefficient that is 0,604 at 30 m/s speed and 0,577 at 15o C temperature, meanwhile for the highest drag coefficient that is 0,039 at 5 m/s speed and 0,0335 at 40o C temperature. The lowest lift coefficient that is 0,547 at 5 m/s speed and 0,569 at 40o C temperature, meanwhile for the lowest drag coefficient thats is 0,032 at 30 m/s speed and 0,331 at 15o C temperature

Uji Karakteristik Hipotesis Bangunan Rumah Tinggal yang Memanfaatkan Pendinginan Evaporasi dengan Computational Fluids Dynamics (CFD)

Air conditioning in housing is required to obtain thermal comfort zone, especially at urban areas that have problems with the limitations of land. One of alternative room air conditioning (AC) that environmently-friendly to reduce refrigeration system is evaporative cooling system. The aim of the research is to investigate characteristic of air conditioning inside the house wich utilize evaporative cooling system using Computational fluids dynamics (CFD ). The research was done by describing 3 different times which are 09.00-10.00 (in the morning), 12.00-13.00 (at noon) and 19.00-20.00 (at night) with incoming air in different properties. The air characteristic test was done by measuring velocity of the wind, relative humidity (RH) and temperatures at 28 positions of measurement cup (PU), where PU were spreaded at 3 places, (1) in front of the house; (2) at the interior; and (3) at the exterior. The measurement was conducted by making square plane of 2x2m with high of 1.5 m above floor of 28 PU. CFD simulation results showed that the cooling effect evaporative felt on the 1st floor with the average temperature reduction of 1.5 oC from the ambient temperature and increase RH of 6.75 % from ambient RH. While the vertical ventilation work effectively in supporting air circulation. The movement of the wind can be felt throughout the house with the average velocity of 0,175 m/s. Key Words : Comfort zone, Evaporative cooling, CF

Analisa Pengaruh Posisi Sail Dan Penambahan Takik Pada Tail Terhadap Hambatan Kapal Selam Dengan Metode Komputasional

Submarines are used for means of transportation in the sea thus requiring designs to minimize the drag force. The purpose of this study is to optimize the location of the sail and the addition of a notch on the tail of submarine. The research was done by simulation approach. The simulation is done in two stages, the first is to change the position of submarine sail, with model variation R2, R2.9 (3D), R3 and R4. From the first stage obtained the best variation model, that is the variation model R3 with Cd = 0.09222. Phase Two, the addition of a notch on the tail. The geometry model used is the best variation model at the first stage, ie the variation model of R3. At this stage there are four variations, namely T1 (without notch), T2 (3 notches), T3 (4 notches), and T4 (5 notches). Notch profile there are three, namely profile HT05, GOE444 and arbitrary. The simulation result was obtained the best geometry model on T1 variation model with notch profile HT05 with Cd = 0.08115

Analisa Pola Aliran Pada Bodi Bus Evonext Standar dengan Evonext Modifikasi Menggunakan CFD (Computational Fluid Dynamic)

The purpose of this research is to model and simulate aerodynamic behavior in bus vehicles with Front Roof and Rear Roof radius changes using CFD. The research is also intended to describe the fluid flow phenomena that occured around the bus vehicle. In this simulation process has been done modification Bus body on Front Roof and Rear Roof radius, speed varied between 60 km an hour to 140 km an hour. The model made in the original scale is intended to describe the flow behavior both in front of and behind the bus vehicle. The simulation was done on steady state condition. The results showed that the lowest coefficient of Drag occurred on the Bus Evonext modified radius Front Roof R1000 and Rear Roof R350 radius modification is 0.398 and the value of Drag coefficient on the standard bus is 0.453. It can be concluded that the modification of the bus on the Front Roof and the Rear Roof was able to lower the Drag force received by the bus

Studi Karakteristik Aerodinamika Model Mobil Menyerupai Chevrolet Camaro Secara Komputasi dan Eksperimen

Development in a car is a body design. The design of the car is not only in terms of aesthetic factors (beauty) but based on the shape of aerodynamics on the body. The purpose of this research is to simulate aerodynamic behavior in car body resembles chevrolet camaro. The study was also intended to investigate the results of drag and lift coefficients between computational methods and experiments with varying speeds. After that in the study made the modification of the angle on the rear bampers and the angle of the windshield. From the simulation result is expressed with descending drag force on car body in the form of data and graph at angle bamper 10º and modification of wind angle of 152º. It can be concluded that the modification of the car on the slope of the windshield and the rear bampers can provide a drag force effect

Studi Pengaruh Variasi Radius Spoiler MCX- Sp Dan Penambahan Tail Dengan Variasi Sudut 5°, 10° Dan 20° Terhadap Hambatan Truk Dengan Metode Komputational

The use of trucks as a means of transporting goods inter provinces in Indonesia very much. The non-aerodynamic form of a truck vehicle in Indonesia has caused major flow resistance. Installation of aerodynamic device spoiler and tail trucks into a solution to reduce barriers on trucking vehicles. By modifying the spoiler radius and tail angle variation, it is expected to reduce the resistance force in the truck vehicle. The purpose of this research was to understand the effect of radius variation on MCX-2 Sp spoiler usage and the addition of tail on the truck vehicle to the drag resistance style that arises when the truck was driving at a speed of 90 km/h using CFD method. The research was developed by from research conducted by Jawi, H.P (2016). The result of the research shows that MCX-2 Sp spoiler radius is the best to reduce the resistance is radius R1000. Further observations on the 5°, 10°,15° and 20° tail variations were performed using MCX-2 Sp R1000 spoiler as reference at the time of simulation. The 5° tail angle variation has optimal performanced