Novel Electronic Cooling Research

♦ Current Research

Study for Phase Change Cooling for Densely packed Electronic Package

Rapid development in the design of electronic packages in the semiconductor industry has led to very high heat flux (80-100 W/cm^2) on the chip surface. Air cooling using conventional materials such as aluminum and copper is not capable for removing such high heat fluxs for maintaining a proper operational temperature. It is imperative to explore new techniques to cool high-speed electronic components. Metal and graphite foams are novel high thermal conductivity materials with large surface areas of between 500 and 10,000 m^2/m^3.

It is conceivable that applying porous foams in phase change system will provide extremely large contact surface area between the solid and fluid phases , which will significantly increase the overall heat transfer performance. The aim of the research is yo utilise the capacity of porous evaporators and to develop guidelines for design of an an effective and compact cooling device for densely-packed electronic packages.

 

Master of Eng thesis

♦ Monitoring of Bearing Defects using Acoustic Emission (AE) Application

Collaborative research UM, UGM, and AUN/Seed-Net JICA (2005-2007)

Acoustic Emission (AE) was developed for non-destructive testing of static and dynamic structures. Over the years AE application has been extended for monitoring of rotating machines and bearings. Bearing is an important part of a rotating machine. Bearing condition monitoring has received considerable attention for many years because the majority of problems in rotating machines are caused by bearing defects. The quality and condition of bearing must be monitored to ensure the quality of machining and machine performance.

Bearings condition can be monitored using an Acoustic Emission (AE) sensor and signal processing apparatus. The AE characteristics can provide useful information about the bearing conditions and detect when the defects occurred. This research focused on the application of AE characteristic on the ball bearing monitoring. Simulated ball defects and inner race defect were applied. The results of this research was validated the use of AE root mean square (r.m.s) and counts in detecting the bearing defects.

 

Bachelor Degree Thesis

♦ Design for Ice Skating Refrigeration System on Malioboro Mall Yogyakarta

Bachelor Degree Thesis (2004) in Bahasa Indonesia

Supervised by: Dr. Ir. Samsul Kamal, MSME

Abstract:

This research has designed a system and main equipments of the ice skating refrigeration machine in the Malioboro mall Yogyakarta. The work has included these steps: literature data study, process and material selection, calculation of the main equipments and piping system, and detailed 2D and 3D CAD drawing. Its also provide the important parameters and information for each materials and equipments based on actual survey data and literature study. The dimension of the ice pool is 30 m x 20 m. Two stages of refrigeration system were used. First stage is the compression system used R-134a as refrigerant. The first cycle contains four main equipments such as: shell and tube evaporator, reciprocating compressor, shell and tube condenser, and expansion valve. This cycle provided cool brine with temperature -15 ⁰ C, and circulate to pipes arrangement to freeze the water on the pool. This brine circulation is called second stage of the refrigeration. The ice temperature maintained at temperature -10 ⁰C with the thickness 15 cm. This system designed to provide the ice land with the ice quality for ice skating standard.