APLIKASI HELMHOLTZ RESONATOR DENGAN VARIASI JUMLAH MONONECK DALAM ARAH LONGITUDINAL PADA INLET MANIFOLD MOTOR DIESEL SUPERCHARGING 4 TAK

Penelitian ini bertujuan untuk mengetahui pengaruh Circular Helmholtz Resonator dengan variasi jumlah Mononec pipa kapiler terhadap Supercharging yang digerakan elektromotor. Penelitian eksperimenal ini dilakukan dengan 6 variasi Mononeck yang dipasang secara longitudinal up side down. Piezotronics, National Instrument dan Matlab digunakan untuk mengakuisisi data menjadi lebih akurat. Hasil pengukuran selisih rata-rata tekanan output dan input menyatakan bahwa Circular Helmholtz Resonator berpengaruh terhadap tekanan udara keluaran yang merupakan tekana udara input motor diesel

PERILAKU CHAOS ALIRAN FLUIDA BERDENYUT DALAM SALURAN BERPENAMPANG SEGIEMPAT

The pulsatile fluid flow in a transverse grooved channel would become chaotic flows in low Reynold numbers. The Reynold number where flows become chaos depends on grooves distances. The objective of this research is to analyze the effect of grooves distances on the behavior of chaos. This research was done by implementing a closed square cross-section channel, where the bottom surface of the channel was semicircle grooved. The frequency of flow oscillation measurement was done by setting up a resistance sensor that is Wheatstone bridge where the resistance sensor was located in a U manometer. Measurement was done at several Reynold number. From the research result, it is seen that the periodic fluid flows in the transverse grooved channel had become chaos at Reynold number Re 950 in the channel without grooved and at Reynold number Re 700 in the grooved channel. Chaos took placed since a vortex appeared at every treatment

STUDI EKSPERIMENTAL PERFORMANCE KAVITASI WATERJET PROPULSI

Cavitation is a complex phenomenon of dynamic processes in hydraulic machines that can cause a decrease in energy performance, vibration and damage the blade surfaces. Analysis of cavitation symptoms in hydraulic machines is carried out through cavitation performance studies, namely the relations between energy parameters. Each hydraulic machine has a critical value on a different cavitation performance curve. Therefore, a study of the effect of cavitation changes is needed to determine the working zone of hydraulic machines without cavitation. In this study, cavitation performance analysis was carried out on a waterjet propulsor model with 5 impeller blades and 7 stator blades using experimental methods. The cavitation coefficient was varied at σ = 2.25 to 0.25 by setting and controlling the inlet pressure on the cavitation test rig. The critical point value will be observed at the point where the thrust coefficient decreased to 3.28%.  The results showed that cavitation begins at σ = 1, the critical point is obtained at σ = 0.75. From these studies, we find that waterjet must be operated at conditions where is σ > 0.75