Publikasi ilmiah
Page ini berisi informasi mengenai publikasi ilmiah dari M. Hilman Gumelar Syafei. Berikut masing-masing abstract, serta link untuk mengaskes full papernya.
1. Analysis of the Effects of Overflow Leakage on Archimedes Turbine Efficiency
ABSTRACT
In Indonesia, 2,519 villages do not have access to electricity because its location is difficult to access. Utilizing the small-scale hydropower by using pico hydro type Archimedes turbine could be an alternative solution. Archimedes turbine has a suitable characteristic to operate under low head condition with a wide range of water discharge. This study aims to determine the value of critical slope angle ( ) that causes overflow leakage and to observe the effect of variation of turbine slope angle towards the turbine efficiency. This study is conducted by analytical method and followed by experimental method. The analytical result shows that the critical value of the slope angle depends on the turbine outer radius and the water volume flow rate. However, there is a contradiction between the analytical result and the experimental result. Based on the analytical result, the turbine efficiency is dramatically decreased when the turbine slope is raised, especially when it surpasses its critical value. On the other hand, the experimental result shows that the efficiency is increased as the slope angle (α) increased. It can be concluded that the overflow leakage is not decreased, significantly, the turbine efficiency. It means that the overflow leakage does not give any losses and the determination of the critical value of slope angle ( ) to prevent overflow leakage is unnecessary.
Link to Full Paper : [1]
2. Investigation of the α angle's effect on the Performance of an Archimedes Turbine
ABSTRACT
Pico hydro can be used as an independent power source to generate power in remote areas. It is also considered to be a solution to the problem of providing electricity to remote areas; this is because its investment and operational costs are lower than wind turbines and solar photovoltaic (PV) systems. The pico hydro type Archimedes turbine is suitable to operate under low head (< 5 m) and in a wide range of discharge conditions. However, one of the problems in the implementation of Archimedes turbines is the optimum α angle (slope angle) values. Several studies (both experimental and modelling) have yielded different optimum α angle (slope angle) values. The present study investigated the α angle’s effect on an Archimedes turbine’s performance; this was done through the experimental method. The experimental method was chosen to determine the output power of the turbine and to study the phenomenon of overflow leakage losses in the energy conversion process. The experiment was conducted with a discharge of 0.00106 m3/s, an α angle between 360 and 440, and three different loads: 100 Watt (1 load), 200 Watt (2 load), and 300 Watt (3 load). Based on the experiment, the higher α angle generated more power but less turbine efficiency; this was because the value of the effective head increased, which also increased the available power. However, the decrease in efficiency was not significant. This proved that the α angle does not heavily influence the amount of power generated. In addition, the prediction that overflow causes loss when the angle α increases was found to be inaccurate – as the power and efficiency of the turbine increased when overflow occurred (overflow was still converted into water weight energy before being absorbed into the shaft). Moreover, the overflow was influenced more by the load value than by the value of the α angle. Thus, the α angle does not greatly affect the amount of power generated. However, the overflow and the value of the load affect the performance of the turbine.
Link to Full Paper: [2]
3. Development of Archimedes Turbine Research: Review Paper
ABSTRACT
Archimedes crew was used as a pump initially, however with time there were many innovations that were done to convert it into power machine. Even though this turbine has been utilized for a considerable time, Archimedes turbine does not have a fixed theory of design. There are several theories that have been developed for this turbine which are related to find out the effects of the angle with the torque that can be absorbed by the turbine. This is done, also to find out the optimum volume of the bucket. These theories are obtained by experimental means. Up to this day, several studies have tried to identify the relationships between optimum angle of screw, effect of pitch and slant to the turbine speed, and relation of rotational speed with friction.
full paper link : [3]
