Pengendalian Pasif Terhadap Boundary Layer Di Flat-Walled Diffuser 20° Dengan Suction Dan Blowing Melalui Rectangular Slot

Nugroho, Rinenggo (2007) Pengendalian Pasif Terhadap Boundary Layer Di Flat-Walled Diffuser 20° Dengan Suction Dan Blowing Melalui Rectangular Slot. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Difuser merupakan salah satu komponen teknik yang berfungsi untuk meningkatkan tekanan aliran fluida dengan cara memperlambat kecepatan aliran. Adanya peningkatan tekanan menghasilkan adverse pressure gradient yang menghambat aliran sehingga boundary layer berkembang dengan cepat dan terjadi separasi aliran. Hal tersebut mengakibatkan performa difuser menjadi drop. 0leh karena itu sudah - banyak penelitian yang difokuskan untuk mengendalikan perkembangan boundary layer di dalam difuser, salah satunya adalah dengan simultaneous suction dan blowing melalui rectangular slot. Penelitian ini bertujuan untuk mengetahui pengaruh suction dan blowing terhadap performa difuser yang dinyatakan sebagai pressure recovery coefficient (Cp). Test section pada penelitian ini berupa flat-walled diffuser dengan sudut divergensi (20) = 20°, tinggi inlet (W J = 50 mm, Iebar span (b) = 100 mm, slenderness (UW1) = 10, dan area ratio (A j A1) = 3,64. Bilangan Reynolds yang digunakan berdasarkan tinggi inlet adalah Rew1 = 5, 6 x I 04 dan Rew1 = 8, 7 x I 04 Pengendali pas if berupa slot blowing dan suction ditempatkan secara simetri pada upper dan lower diverging wall, masing - masing pada x/L = 0,1 dan x/L = 0,5. Tiga sudut kemiringan slot blowing sebesar 45°, 30°, dan 15° digunakan pada penelitian ini. Tekanan stagnasi diukur dengan menggunakan Pilot tube pada beberapa cross section untuk mendapatkan distribusi profil kecepatan rata - rata. Tekanan statis diukur dengan wall pressure tap yang ditempatkan mulai diffuser inlet (x/L = 0) sampai diffuser outlet (x/L = 1) dengan jarak antar tap sebesar 5 mm untuk mendapatkan distribusi wall pressure recovery coefficient (Cp). Data tekanan stagnasi bersama dengan tekanan statis digunakan untuk menghitung harga skin friction coefficient (Cf) berdasarkan metode Preston tube. Hasil yang dicapai pada penelitian ini adalah adanya peningkatan pressure recovery coefficient (Cp) sebesar 15 % dan 10 % pada bilangan Reynolds rendah untuk sudut kemiringan slot blowing 45° dan 30°. Sedangkan pada bilangan Reynolds yang tinggi, tidak dihasilkan peningkatan Cp sama sekali untuk seluruh harga sudut blowing yang digunakan
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A diffuser is a technical component that increases fluid flow pressure by slowing the flow velocity. This increase in pressure produces an adverse pressure gradient that inhibits flow, causing the boundary layer to develop rapidly and flow separation to occur. This results in decreased diffuser performance. Therefore, much research has focused on controlling boundary layer development within diffusers, one of which is the simultaneous suction and blowing of fluid through rectangular slots. This study aims to determine the effect of suction and blowing on diffuser performance, expressed as the pressure recovery coefficient (Cp). The test section in this study was a flat-walled diffuser with a divergence angle (20) = 20°, inlet height (W J = 50 mm, span width (b) = 100 mm, slenderness (UW1) = 10, and area ratio (A j A1) = 3.64. The Reynolds number used based on the inlet height was Rew1 = 5.6 x I 04 and Rew1 = 8.7 x I 04. The pass-through controllers in the form of blowing and suction slots were placed symmetrically on the upper and lower diverging walls, respectively at x/L = 0.1 and x/L = 0.5. Three blowing slot inclination angles of 45°, 30°, and 15° were used in this study. The stagnation pressure was measured using a pilot tube on several cross sections to obtain the average velocity profile distribution. The static pressure was measured with a wall pressure tap placed from the diffuser inlet (x/L = 0) to the diffuser inlet (x/L = 0). outlet (x/L = 1) with a tap spacing of 5 mm to obtain the wall pressure recovery coefficient (Cp) distribution. Stagnation pressure data along with static pressure are used to calculate the skin friction coefficient (Cf) based on the Preston tube method. The results achieved in this study are an increase in the pressure recovery coefficient (Cp) of 15% and 10% at low Reynolds numbers for blowing slot angles of 45° and 30°, respectively. Meanwhile, at high Reynolds numbers, no increase in Cp was produced at all for all blowing angles. used

Item Type:	Thesis (Other)
Additional Information:	RSM 620.106 Nug p-1 2007 (weeding)
Uncontrolled Keywords:	Difuser, pressure recovery coefficient (Cp), suction, blowing, tegangan geser dinding; Diffuser, pressure recovery coefficient (Cp), suction, blowing, wall shear stress
Subjects:	Q Science > QC Physics > QC151 Fluid dynamics
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	EKO BUDI RAHARJO
Date Deposited:	15 Oct 2025 07:12
Last Modified:	15 Oct 2025 07:12
URI:	http://repository.its.ac.id/id/eprint/128595

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