Experimental investigation of a liquid film formed by impingement of an axisymmetric jet on a flat heated surface

• Autorzy: Bykuć S.
• Konferencja: "Modelling and Multiphase Flows in Thermo-Chemical Systems. Advanced Measurement Techniques" / sympozjum [5th; September 2nd to 4th, 2005; Stawiska near Gdansk, Poland]
• Języki publikacji: EN

Abstrakty

EN

The aim of the present work was to study experimentally hydrodynamic and heat transfer characteristics of the flow of a liquid film over a surface. A round jet of water impinging vertically on a horizontal plane forms a thin film flowing radially until the sudden increase of depth occurs (hydraulic jump). During the experiment, the temperature of the solid surface and liquid film thickness in the suhcritical region (downstream of the hydraulic jump) and supercritical region (upstream of the hydraulic jump) were measured. Radial film thickness and Nusselt number distributions were achieved. Experiments were performed for a range of flow rates between 0.3 and 0.8 I/min. The liquid film thickness upstream of the hydraulic jump was an order of magnitude smaller than that of the subcritical region. With the growth of the flow rate, the radius of the hydraulic jump and film thickness after the jump, increased. It was found that the local Nusselt number reached maximum near the stagnation region and decreases gradually with radius as the flow moves downstream with the biggest drop corresponding to the location of hydraulic jump. Downstream of the jump, Nu was approximately uniform. Higher Nusselt numbers were reached for higher flow rates. These differences for various flow rates were much bigger in the supercritical region than that in the subcritical one.

Słowa kluczowe

EN

jet impingement; hydraulic jump; liquid film thickness; local heat transfer

PL

uderzenie strumienia; odskok hydrauliczny; warstwa cieczy; grubość; transport ciepła

• Wydawca: Wydawnictwo Politechniki Częstochowskiej
• Czasopismo: Turbulence : international journal
• Rocznik: 2005
• Tom: Vol. 11
• Strony: 235--237
• Opis fizyczny: Bibliogr. 5 poz.

Twórcy

autor

Bykuć S.

• The Szewalski Institute of Fluild-Flow Machinery, Polish Academy of Sciences Fiszera 14, 80-952 Gdańsk, Poland

Bibliografia

• [1] Watson EJ., The radial spread of a liquid jet over a horizontal plane, J. Fluid Mech. 1964, 20.
• [2] Chaudhury Z.H., Heat transfer in a radial liquid jet, J. Fluid Mech. 1964, 20.
• [3] Azuma T., Hoshino T., The radial flow of a thin liquid film, Bulletin of JSME 1984, 27, 234 December.
• [4] Carper H.J., Impingement cooling by liquid jet, Am. Soc. Mech. Eng, Heat Transfer Div. 1989.
• [5] Mikielewicz J., Mikielewicz D., Spreading of impinging liquid film on an inclined plate, Proc. 2nd Int. Conference on Heat Transfer and Transport Phenomena in Multiphase Systems, Kielce 18-22 May 1999.