Pengamatan Gerak Konveksi Rayleigh-benard Sebagai Fungsi Perbedaan Suhu

Abstract

Telah dibuat sebuah alat pengamatan konveksi Rayleigh-Benard (RBC) dari bahan kaca berbentuk kotak yang dibatasi dengan dua reservoir horizontal yaitu reservoir panas dan reservoir dingin. Pada alat ini dilengkapi automatic thermo-controller sebagai pengatur suhu reservoir panas. Air sebagai media yang diamati dinamika fluidanya yang mana gerakan fluida direpresentasikan oleh serbuk gergaji kayu jati (SGKJ). Hasil pengamatan memperlihatkan bahwa perbedaan suhu (∆T) antara reservoir panas dan reservoir dingin berperan penting terhadap kecepatan gerak molekul air, jari-jari konveksi, dan pola aliran molekul air. Kenaikan ∆T menyebabkan kenaikan kecepatan gerak molekul air yang ditampilkan dengan diagram percabangan, namun ukuran jari-jari konveksi mengalami penurunan. Selain itu diamati juga pola aliran molekul air terhadap kenaikan ∆T.An observation tool of Rayleigh-Benard Convection (RBC) has been made from glass shaped box that bounded by two horizontal reservoirs, i.e. hot and cold reservoirs. In this tool an automatic thermo-controller is installed in the hot reservoir as temperature control. Water as media for the observed the fluid dynamics that the fluid motion is represented by the teak sawdust. The observations show that the temperature difference (ΔT) between the hot and cold reservoirs plays an important role on the velocity of water molecules, the radius of convection, and molecules flow pattern of water. Increasing ΔT causes the increase in the velocity of water molecules that is shown by bifurcation diagram, however the radius of the convection is monotonically decrease. In addition, it was also observed the molecules flow pattern of water to the increase in ΔT