-. i -- TOFL. ORNL P 1447 . . , . $0 40 FA MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS – 1963 Walang Talame . . II ORNp .) 4 will A New Similarity Parameter for Corrolation of Jet Pump Cavitetton. * Molvin E. LaVerne Oak Ridge National Laboratory MAS Oak Ridge, Tennessee WNK-657110-4 ABSTRACT: 'SULO 1965 The corresponding dimensionloss groups obtained from a dimensional bouw analysis of centrifugal and get pump performance are compared in this paper. A new characteristic parameter for the correlation of jet pump cavitation performance is derived from the comparison, the new parameter being the analog of suction specific speed for a centrifugal pump. Data ere presented to illustrate the correlating ability of the parameter. -LEGAL NOTICE PROVED FOR POETS RELEASE. AVAILABLE DHE NEARD ITS CONTRACTORS ONLY NO It is the object of this paper to exploit the basic similarities between centrifugal and jet pumps to construct, for the jet pump, a set of dimensionless parameters completely analogous to those employed for the presentation of centrifugal pump performance. In particular, the jet pump analog of centrifugal pump suction specific speed will be derived for correlation of Jet pump cavitation performance. - C. Basically, the centrifugal and jet pumps differ only in the method employed to transfer energy to the pumped fluid. The centrifugal pump utilizes rotation of an impeller disc; the jet pump employs injection of a high-velocity jet. monsored work. Neidhor the United Commission: dir report, or that www ploto or contract ol, er for damagos meoutes from the hell of the coun..ton" incinden wy do- to N. and n parna ithe a bella A. Makes uyrruty or repreenutou, pred or implied, we respect to the accu- formation of my taformation, appunto, Lthod, UT procons declared in the sport uy bol latring This roport me prepared an account of Gove. U tutordon part am of my buforation, apontu, pothod, or proces declerod la to report. poyo or contractor of the Corniolon, or empleyw of much contractor, to the onoat that of such as playas or contractor of the Couvostou, or onployna of mica contractor koparu, B. Around Any liabilities with roape to the w tulo, tor de Corunclan, mer w ue; or racy, completeness, or whales As wwd la the bene, "prio ita wju the Counaton, or No sployment with auch contractar. dissoninster, or provide acces do, w prietely owned r Let us begin with a hasty review of the performance analysis for a series of geometrically similar centrifugal pumps. We shall be IN NUCLEAR SCIENCE ABSTRACTS RELEASIOD FOR ANNOUNCEMENT concerned "irst with pump head-rise H, and its dependence on the density P and viscosity M of the pumped fluid, the volume flow-rato Q, impeller size D, and rotational speed n. The treatment of gravitational acceleration g as a separate variable is avoided by taking the product gH as the dependent variable. We therefore assume (2) H . f (PM; Q, D, n) *Research sponsored by the U. 3. Atomic Energy Commission under contract with the Union Carbide Corporation. (1) "An Introduction to Fluid Mechanics and Heat Transfer", J. M. Kay, University Press, Cambridge, 1957, pp. 88-92. o ... ... ..- Dimens..onal analysis then reduces this function to the simpler dimensionless · relationship 2 2 where the three dimensionless groups are a head coefhcient, a flow coeficient, and a Reynolds number, respectively. A parameter involving only pump operating conditions may be conecruated by elimination of impeller diameter between the head flow coefficients. With the proviso that roational speed appear linearly, this yields the dimensionless specific speed, - - - -- - -- - - - - - - - - - - - -- - - - - - - - -3- Turning our attention now to cavitation performance, it has been shown (2) that similarity of cavitation conditions is attained if the Thoma parameter 0 , 1.6., the ratio of net suction head Hor to pump hisad I, is held constant for similar flow conditions, the latter imp2ying constancy of specific speed. Eliminating, H between o ad ng then yields a parameter involving only inlet conditions. This parameter is, of course, the suction specific speed. In dimensionless form, SenVQ (9Hs 1234 It is this last quantity whose jet pump analog 18 sought. Nozzle head-difference Hy and nozzle flow by yield a measure of the energy input to the jet pump; impeller size and rotative speed serve the (2) nCavitation Characteristics of Centrifugal Pumps Described by Similarity Considerations", G, F. Wislicenus, R. M. Watson, and I. J. Karassik, Trans ASME, Vol. , 1939, pp. 17-24. - -- - - - - - same function for the centrifugal pump. Let us therefore begin the analysis by replacing n and D by gin and QN. We than hare gH = fgle, M, Q,Qw, JHw) Equation -5may be reduced to learn, pešcu)) as in equation -2-. Comparing corresponding groups in equations -2- and -6-, we obtain Table 1, which shows equivalent quantities for the two pumps. The first three lines of Table 1 weru obtai.ned directly from equations -2- and -6-3 only two o.? these equivalerice-pairs are independent, of course, any one being derivable from the other two. The remaining two equivalence-pairs result from eliminating n and D, respectivel5', in the first three lines. The Jet pump analog of specific speed is then obtained from equation - 3- and Table 1. - Finally, we obtain the jet-pump analog of suction specific speed from equation -4- and Table 1 as My - Co Jest to Si = The right-hand side of equation -8-'is the new cavitation correlation parameter. Figure 1 shows ORNL data plotted on the usual head coefficient versus flow coefficient coordinates for both non-cavitating and cavitating operation of a jet pump. The non-cavitating data were taken with a large submergence on the pump. The cavitating data were taken by a reducing the net suction head to the values shown on the figure and forcing the pump into cavitation by increasing nozzle flow. The hook shape of the curves is characteristio. The oavitation data of Mg. 1 are correlated in Fig. 2 in terms of a cavitation coefficient and the cavitation parameter. Sy. The cavitation coefficient is defined as the ratio of the caritating to the non-cavitating head ratio. On the basis of the limited data presented, the correlation seems quite good. In summary, then, dimensional analyses were made of centrifugal And jet pump performance. Equivalence-pairs were determined from a comparison of corresponding dimensionless groups. From these equivalence-pairs and definitions for the centrifugal pump were obtained the jet pump analogs of specifio speed and suction specific speed, not and Sgo respectively. S, was applied to the correlation of a limited amount of jet pump cavitation data with promising results. Watches de entitatea de po on a Table 1 Centrifugal and jet pump equivalents derived from a dimensional analysis. Centrifugal Pump Jet Pump gHN @x1/2 (EXy) /4 ()-2/4 2/2 (84) 3/4 . -1/2 huano hitno... Lesbian Li ** . *** 0000000000NNIOINTI LION IIIIIIIIIIIIIIIIIUTTUUT D1 100 DUIIIII DIIIIIIIIIIIIIIIIIIII LUULUULUIIIIII 100001 UUUUUUUUUUU UUTUUDIO WUUUUUUUUUUUU UUDIOOTIIUI H00MILO 10000100IIIIIIIIIIIIIIII 10000 UDUTULIUOTO001 DITIINIDDIU DODIO 00000000101010 UUUUUUUUUUNIIN WU10 UDDIN DIIDIIDIINU TOOMIDOLLO0D UUUUUUUUUUUUUUUU ILUUUUUU11UUIO 00LIU QUI UUUUUUUULLIU OIOITUITID 10 DUIIIII IIIIIIIIIII MTOTOLINI NOOITOL ULDUULOUUU. QI0110011011011111111 VUULLI III 000II1II021000TIIIIIII NU WIDUULUI IIIIIIIIIIII TIDO DINIS I UDIO DO III DODUOTUUT DUUUUUUUUUUUUUUUUUUU IIIU 10DULU QUILUUIILOILUUUUUU DIUTIUI CLITOIIDIIIII 0101001110 IONI100001010011000r. COLOU000 :-* 100 : UNDIT Cavitating, 3.0 in 40 suppression head Cavitating, 4.5 in 1.0 suppression head Non-cavitating LEGEND ITU ... IIIIIIULIUUUUU 1100 TITUIT UUUUULUISURE DITUUUUUUUUUUULIUO ODIUULI 00000 2010 LITIO Q1I0000OOOMUUT 01100 JUUIUDIIDIIDID UUUUUULI UITIUITOUTU 100IIIIIIIII11100000011 0000000 00DID OMULUT DOO UUUUUUUUUUUUUU TUDII10111110010100 101 11011 UUUUUUUUU 001 IDIIDIIDID 000000 TII 0001 DUUUUUUUUUUU IIIIIIIIIIIIIIIIIII IIIIII TTT .. UUUUUUUUUUUUUU MUUUUUU III INDUIDINIU DIITIDUNUD ILIULITUD . : UUUUUUUUUUUU DIDINIDIONI JUUUUUUUUUUUUUUUUUUU ID OU NONTO UUDOUDO 00000101 UUUUUUUUU IIIIIIIII 100000 TWITT LIIIIIIIIIIIIIIIII UUUUUUUUU UDUTULIINIT LULIIIIIIIDID UUUUUUDIO 110UIA ITINUTUD LUULUUUUUUUUUUUUUU UULINOIVUILNIIIII IOITUTIUUMIL FLOW RATIO, Ø 10 IIIIIIITTIT 78. 1. Performance of a Jet Pwap under Moncavitating and Cavitating Conditions. Nozzle-to-Throat Area-Ratio - 0.107. 0000000000000000000 01010100 IOTT LUULUUDILUUUUULL LUUIIIIIIIIIIIII UUUUUUUUUUUUUUUL ULIIIIIIIIIUU UUUUUUUUUUUUUU DOOD OIIOIO IIIMIIIIINOO OL IIIDUIIIIIIIIIII COILUUUU DUIDIN UTIONULUI DU1UUIO KIDUDOU WolLOUDU 000 MILITUD TI VOITIITITIT, III'O ILUUIIIIIII 04OTODD INNTIT INTU NOTITIONDONI TUTUMINIO IDIOUTO0IIIIIIII ILO WUU TUDI UNDURO INDI III TIITITTI OUT UCION: TULO 001, 0100 WINDI CUTIT C UIDIDUNUDO ULUIINUUD OIIND 000 DONUN 10TIA TUOUIDID OMNIT ULTIUNI 1011100 100T ILII DIID IUIDUTINU 00DIUTI ODE DIO MINIO OUTIDUD UUUUUUUIUIU OLIITIL 100MLIN10 U100 UUUUUUUUUUU LICIT WITIONUJIITIUUTO OUDOUDO OI N'OLIV SUNSSA - OW001000 IN 00000 DIDIOUDU 00000000 UUUUUUUUUU 0000000000 JUULUUOO 000 WOUUUUUULIIDID 00UNOUN PO 10000000000000 DULOUWD (Q/Qn)/ DIOTOILUOTOUUUUUUUUUUU UUUUUUUUUUUUUUUUUU 000000U 000001001 10010000 0000000UUUUU 000 00000 100 0001nIT OIDUD TUTUNUTDUMIINID 100000 1000 CUVUUUUUUUUUHDII awu...000.000.000 1000 11010 (NI000000000000 OM DIODOTTO 000000 0IDO DWUT ONI00000 DWU000000 000000000UUUUU 000000000010 100000UUUUUUU. PUUDUILL Mg. 2. Cavitation Performance of a Jet Pump as a function of the Nozzle-to-Throat Area-Ratio - 0.107. Cavitation Parameter S, 20 CUUUUUUUII Cavitation Parameter S1, (in/igy)" 0001 VIII00 101 SUDIO 100 UTIC 0100 000 : 10 0 000 1000 осоос DIIII10000 OI001WOT 01000000 ITUITOUDUIT DIDUUUUID ODIDUUDULIDI UUUUUUUUUUUUU UDODILOITUUT DII100001 L0UUUUU ID0001 DOUD 0010 UIDOO (LUDINO DOO ULOUUDIIDII UUUUUUUUDUDIO DU0000000000000000000 ODLOODUDUUUUU LOUIDIOODILIUTITI WUUUUUUUUUUL IIIIIIIIIDIUUUUUUUUUUU 00000000 OUTINUIDHIDI DODIIDII. LU00DD UUUUUUUUIILUL MOUWD 0100000000 OIIIIIIDID 0000000000 1000IWIOL JULIDUUDIS 00000000000000 N DONII UUUUUUUUUUU LILITOITUT DULODUNI OMNIUOOUUTIOILUUUUUUUU NUMIDO100UIOON UU IULUIUIDUUUUUUUUUUUUUU UUUUUUUUUUUUUUUUUUUUUUUUUU WUUUUUUUUUUUU0000000UILIVUDOUDU OUVI SAN/N 'quafondjáOJ Qo7787 11B) END DATE FILMED 11/ 17 /65 2.. 8. -