Browsing by Author "Utama, Ikap"

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    ANALISA DISTRIBUSI TEKANAN DAN KECEPATAN ALIRAN PADA KAPAL KATAMARAN TANPA TURBULEN STIMULATOR DENGAN UJI TEROWONGAN ANGIN
    (2014-02-04) Hutauruk, Ronald Mangasi; Jamaluddin; Murdijanto; DJONI, I Made Arya; Utama, Ikap
    Catamaran consists of two demihulls which are separated at certain distance. Both of demihulls induce interaction that generates viscous interference. Due to separation to length ratio between demihulls, interference effect occurs significantly over viscous resistance. These interference effects will be investigated by doing experimental test in the wind tunnel to analyze the pressure distribution and velocity profile on the catamaran. Catamaran model is designed without transition strip (turbulent stimulator). The models will be tested at various velocities, commenced from 10; 12; 14 dan 15.5 m/s in speed and separation to length ratio (S/L) 0.2, 0.3 and 0.4. Experimental results define that body separation effects both pressure distribution and velocity profile. Increasing of body separation will increase pressure distribution values. However, its increasing will decrease velocity profile values.
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    Wind Tunnel Investigation into the Drag Characteristics of A Pair of Demihull Catamaran in Proximity
    (2014-02-04) Jamaluddin; Hutauruk, Ronald Mangasi; Utama, Ikap
    An experimental investigation into drag characteristics of a pair of demihull catamaran was carried out using low-speed wind tunnel at Department of Mechanical Engineering, Sepuluh Nopember Institute of Technology (ITS), Surabaya. Full viscous drag investigations were performed without and with turbulence transition strip at the range of Reynolds numbers 2.9x105 – 4.5x105. The model hull forms comprise a twin model of hull similar to NPL 4a along which are separated laterally. The results obviously demonstrate the effect of hull separation. The experimental work shows that the pressure coefficient increases while the flow velocity decreases when the hull clearance was closer. Furthermore, viscous drag of model with turbulence strip was higher 1.8% than that of non turbulence strip. The experimental results are presented in tables and graphical forms and the drag characteristics and interference effects are discussed and compared with published data in which show good agreement.