The Chilowsky effect, whereby a jet initially inclined to a flat plate subsequently becomes attached to it, thereby forming an enclosed region of recirculation, has been studied. A quasi-plane cold air jet (at about 0°C) issued parallel or inclined to an adjacent adiabatic flat plate, with a slot-exit Reynolds number <5 times 103, into quiescent ambient air (at about 16°C). The temperature field in and around the jet was mapped using a 15-cm field-of-view Mach-Zehnder interferometer for a downstream distance of 90 slot widths and compared with predictions from Glauert/Seban-Back theoretical model for turbulent wall jets.
Transverse velocity and temperature profiles downstream of the attachment point were found to be near-similar for inclination angles up to 40°. The attaching inclined jets exhibited two wall-temperature decay rates, similar to those observed for three-dimensional wall jets. To utilize the Chilowsky phenomenon, continuous linear air-conditioning diffusers need to be designed with exit angles of less than 50°, thereby ensuring jet attachment to the ceiling and so avoiding discomfort to human occupants.
Get full access to this article
View all access options for this article.
References
1.
HoughtenF. C.GutberletC.WitkowskiE.‘Draft temperatures and velocities in relation to skin temperature and feeling of warmth’, ASHVE Trans.193844, 289–308.
2.
StraubH. E.‘Principles of room air distribution’, Heat. Pip. Air Condit.196941, 122–128.
3.
YousoufianH. H.‘Diffusion and distribution from ceiling and wall outlets’, Heat. Pip. Air Condit.196638, 124–131.
4.
JackmanP. J.‘Air movement in rooms with side-wall mounted grilles: a design procedure’, Laboratory Report No. 65 Heating and Ventilating Research Assoc., Bracknell, England, 1970.
5.
AldridgeK. G.‘Linear air distribution—principles and practice’, Building Services Engineer197240, 167–178.
6.
BourqueC.NewmanB. G.‘Reattachment of a two-dimensional incompressible jet to an adjacent flat plate’, Aero. Quart.196011, 201–232.
7.
NewmanB. G.‘The deflection of plane jets by adjacent boundaries—Coanda effect’, Boundary layer and flow control19611, 232–264 (Pergamon Press, Oxford).
8.
NewmannB. G.‘The prediction of turbulent jets and wall jets’, Canadian Aero. Space J.196915, 288–305.
9.
KumadaM.HeguriH.MabuchiI.‘Studies on heat transfer to turbulent jets with adjacent boundaries (2nd Report, mass transfer to plane turbulent jet reattached on an inclined flat plate)’, Bulletin of JSME197215, 1246–1256.
GlauertM. B.‘The wall jet’, J. Fluid Mech.19561, 625–643.
13.
BakkeP.‘An experimental investigation of a wall jet’, J. Fluid Mech.19572, 467–472.
14.
BradshawP.GeeM. T.‘Turbulent wall jets with and without an external stream’, ARC RM 3252 1960.
15.
SchwarzW. H.CosartW. P.‘The two-dimensional turbulent wall-jet’, J. Fluid Mech.196110, 481–495.
16.
SebanR. A.BackL. H.‘Velocity and temperature profiles in a wall jet’, Int. J. Heat Mass Transfer19613, 255–265.
17.
MyersG. E.SchauerJ. J.EustisR. H.‘Plane turbulent wall jet flow development and friction factor’, J. Basic Engng, Trans. ASME196385D, 47–54.
18.
MyersG. E.SchauerJ. J.EustisR. H.‘Heat transfer to plane turbulent wall jets’, J. Heat Transfer, Trans. ASME196385C, 209–214.
19.
MabuchiI.KumadaM.‘Studies on heat transfer to turbulent jets with adjacent boundaries (1st report, flow development and mass transfer in plane turbulent wall jet)’, Bulletin of JSME197215, 1236–1245.
20.
HariV. M.‘A method to analyse the wall jet flow’, Aero Journal197377, 512–515.
21.
BradshawP.‘Effects of streamline curvature on turbulent flow’, AGARD-AG-169 1973.
22.
MetralA.ZernerF.‘The Coanda effect’, Pub. Sci. et Tech. du Min. de l'Air 1948, 218 (Translated as US AEC-TR-3386).
23.
BrooksR. G.ProbertS. D.MaxwellJ.‘A 15 cm field of view Mach-Zehnder interferometer for heat transfer studies’, Measurement and Control19681, T9–T16.
24.
MetzgerD. E.CarperH. J.SwankL. R.‘Heat transfer with film cooling near nontangential injection slots’, J. Engng Power, Trans. ASME196890A, 157–163.
25.
SivasegaramS.WhitelawJ. H.‘Film cooling slots: The importance of lip thickness and injection angle’, J. mech. Engng Sci.196911, 22–27.
26.
MetzgerD. E.CarperH. J.WarrenJ. M.‘Predicted film cooling near flush slots—comparison with experiment’, J. Aircraft19729, 857–863.
27.
MatthewsL.Performance of some two-dimensional film cooling geometries Ph.D. Thesis, London Univ., 1972.
28.
PorehM.TuseiY. G.CermakJ. E.‘Investigation of a turbulent radial wall jet’, J. appl. Mech., Trans. ASME196734E, 457–463.
29.
KrukaV.EskinaziS.‘The wall-jet in a moving stream’, J. Fluid Mech.196420, 555–579.
30.
KackerS. C.WhitelawJ. H.‘Some properties of the two-dimensional wall jet in a moving stream’, J. appl. Mech., Trans. ASME196835E, 641–651.
31.
KackerS. C.PaiB. R.WhitelawJ. H.‘The prediction of wall jet flows with particular reference to film cooling’, Progress in heat and mass transfer19692, 163–186 (Pergamon Press, Oxford).
32.
KackerS. C.WhitelawJ. H.‘Prediction of wall-jet and wall-wake flows’, J. mech. Engng Sci.197012, 404–420.
33.
MatthewsL.WhitelawJ. H.‘Plane-jet flow over a backward-facing step’, Proc. I. Mech. E.1973187, Paper 38/73.
34.
PatankarS. V.RastogiA. K.WhitelawJ. H.‘The effectiveness of three-dimensional film-cooling slots—II. Predictions’, Int. J. Heat Mass Transfer197316, 1673–1681.
35.
PatankarS. V.SpaldingD. B.Heat and mass transfer in boundary layersSecond Edition, 1970 (Intertext Books, London).
36.
GosmanA. D.PunW. M.RunchalA. K.SpaldingD. B.WolfshteinM.Heat and mass transfer in recirculating flows1969 (Academic Press, London).
37.
PatankarS. V.SpaldingD. B.‘A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows’, Int. J. Heat Mass Transfer197215, 1787–1806.
38.
LaunderB. E.SpaldingD. B.Mathematical models of turbulence1972 (Academic Press, London).
39.
SpaldingD. B.‘The calculation of convective heat transfer in complex flow systems’, Proc. 5th Int. Heat Transfer Conf.19746, 44–60 (Tokyo).
40.
PatankarS. V.‘Numerical prediction of three-dimensional flows’, Studies in convection19751, 1–78 (Academic Press, London).
41.
SchlichtingH.Boundary layer theorySixth Edition, 1968 (McGraw-Hill, New York).
42.
O'CallaghanP. W.ProbertS. D.NewbertG. J.‘Velocity and temperature distributions for cold air jets issuing from linear slot vents into relatively warm air’, J. mech. Engng Sci.197517, 139–149.
43.
Van Der HeggeZijnen B. G.‘Measurements of the velocity distribution in a plane turbulent jet of air’, Appl. Sci. Res.1958A7, 256–276.
44.
HammondG. P.O'CallaghanP. W.ProbertS. D.‘An interferometric study of a cold air jet with by-pass streams issuing into still ambient air’, Applied Energy19762, 141–160.
45.
KovasznayL. S. G.‘Optical techniques’, High speed aerodynamics and jet propulsion. Vol. 9: Physical measurements in gas dynamics and combustion1955, 277–283 (OUP, London).
46.
HaufW.GrigullU.‘Optical methods in heat transfer’, Advances in heat transfer19706, 133–366 (Academic Press, New York).
47.
WilkieD.FisherS. A.‘Measurement of temperature by Mach-Zehnder interferometry’, Proc. I. Mech. E.1963–64178, 461–472.
48.
KestinJ.RichardsonP. D.‘Heat transfer across turbulent incompressible boundary layers’, Int. J. Heat Mass Transfer19636, 167–189.
49.
ReynoldsA. J.‘The prediction of turbulent Prandtl and Schmidt numbers’, Int. J. Heat Mass Transfer197518, 1055–1069.
50.
SforzaP. M.HerbstG.‘A study of three-dimensional, incompressible turbulent wall jets’, AIAA Journal19708, 276–282.
51.
SwamyChandrasekhara N. B.BandyopadhyayP.‘Mean and turbulence characteristics of three-dimensional wall jets’, J. Fluid Mech.197571, 541–562.
52.
KreithF.Principles of heat transferThird Edition, 1973, 405–407 (Intext Press, New York).
