The Department of Mechanical and Industrial Engineering of Gadjah Mada University proudly present the 9th International Conference on Thermofluids 2017. The 9th International Conference on Thermofluids objectives are bringing together researchers, scientists, academics, policy makers and professionals to exchange information and identify research needs in the areas of thermofluids engineering. In this annual conference, we seek to expand the scope to a wider community of researchers allowing a higher quality of knowledge transfer and communication. We hope that by collaborating with the researcher from different country will increase in both the quality and visibility of publications. The conference would also contribute to continuos development of the research and technology in thermofluids engineering for current and future energy and environment sustainability.