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The 90th Anniversary of the Fluids Engineering Division (FED) of ASME will be celebrated on July 10–14, 2016 in Washington, DC. The venue is ASME's Summer Heat Transfer Conference (SHTC), Fluids Engineering Division Summer Meeting (FEDSM), and International Conference on Nanochannels and Microchannels (ICNMM). The occasion is an opportune time to celebrate and reflect on the origin of FED and its predecessor—the Hydraulic Division (HYD), which existed from 1926–1963. Therefore, the FED Executive Committee decided that it would be appropriate to publish concurrently a history of the HYD/FED. Accordingly, they commissioned Paul Cooper, C. Samuel Martin, and Timothy O'Hern to prepare this paper, which would document the division's past. A brief work in this direction had appeared in the 2010 FED Newsletter (Morgan, W. B., 2010, Brief History of ASME's Hydraulic/Fluids Engineering Division, Fluids Engineering Division Newsletter, New York, pp. 6–7), and the research by Martin for the present paper had been under way for several years prior to that (Cooper, P., 2010, “History of the FED,” FED Executive Committee at the ASME-CSME Fluids Engineering Summer Conference (FEDSM-2010), Montréal, QC, Canada, Aug., p. 14).

Experiments were conducted for the purpose of investigating the phenomenon of condensation-induced waterhammer in an ammonia refrigeration system. Waterhammer was initiated by introducing hot ammonia gas over static subcooled ammonia liquid placed in a horizontal 146.3 mm diameter carbon steel pipe approximately 6.0 m long. By means of fast response piezoelectric pressure transducers and a high speed data acquisition system rapid dynamic pressures were recorded whenever a condensation-induced event occurred. Moreover, by means of top-mounted diaphragm pressure transducers sensing gas pressure the speed of liquid slugs propagating along the pipe was determined. Based upon careful interpretation of the results criteria for the transition from initial stratified flow to slug flow were established, similar to the so-called Taitel-Dukler correlation in two-phase flow literature. Kondensationsinduzierte Druckstose in einem horizontalen Rohr. Zur Untersuchung von kondensationsinduzierten Druckstosen in einer Ammoniak-Kalteanlage wurden Experimente an einer Versuchsanlage durchgefuhrt. Kondensationsschlage wurden ausgelost, indem in einem horizontalen, 6 Meter langen Stahlrohr mit einem Durchmesser von 146,3 mm heiser Ammoniak-Dampf uber eine unterkuhlte ruhende Flussigkeitsschicht aus Ammoniak geleitet wurde. Mit Hilfe einer hochtransienten Druck-Messtechnik und einem Hochgeschwindigkeitssystem zur Datenerfassung wurden die dynamischen Drucke, die bei einem Kondensationsschlag auftraten, aufgezeichnet. Daruber hinaus konnte die Geschwindigkeit der entstehenden Flussigkeitspfropfen durch Membran-Druckaufnehmer, die am oberen Scheitel des Rohres angebracht waren, bestimmt werden. Uber eine sorgfaltige Interpretation der Messergebnisse konnte ein Kriterium fur den Ubergang von Schicht- zu Pfropfenstromung aufgestellt werden, vergleichbar mit dem von Taitel-Dukler, das aus der Literatur zu Zweiphasenstromungen bekannt ist.

Simulations of condensation-induced water hammer with one-dimensional two-fluid model requires explicit modeling of slug formation, slug propagation, and in some cases slug decay. Stratified flow correlations that are more or less well known in 1D two-fluid models, are crucial for accurate description of the initial phase of the slug formation and slug propagation. Slug formation means transition to other flow regime that requires different set of correlations. To use such two-fluid model for condensation induced water hammer simulations, a single slug must be explicitly recognized and captured. In the present work two cases of condensation-induced water hammer simulations performed with WAHA code, are described and discussed: injection of cold liquid into horizontal pipe filled with steam and injection of hot steam into horizontal pipe partially filled with cold liquid.

A numerical model based on the method of characteristics is developed to analyze unsteady flows in laboratory ductwork systems. Damper opening and/or closing initiate time-variable boundary conditions at hood inlets. Minor losses and ductwork friction are included, as well as interaction with fans. Extensive data are obtained from two university laboratory systems for purposes of code verification. Comparisons between experiments and simulations demonstrate the accuracy and versatility of the numerical model.

The phenomenon of condensation-induced waterhammer in an ammonia refrigeration system was investigated experimentally. Waterhammer was generated by introducing warm ammonia gas over static subcooled ammonia liquid placed in a horizontal 146.3 mm diameter carbon steel pipe approximately 6.0 m long. By means of fast response piezoelectric pressure transducers and a high speed data acquisition system rapid dynamic pressures were recorded whenever a condensation-induced event occurred. Employing top-mounted diaphragm pressure transducers to sense gas pressure the speed of liquid slugs propagating along the pipe was determined. The occurrence of condensation-induced waterhammer depended upon three major variables; namely, (1) initial liquid depth, (2) liquid temperature, and (3) mass flow rate of warm gas. For given liquid depth and temperature, once the warm gas threshold conditions were exceeded, shocks occurred with greater magnitude as the mass flow rate of warm gas input was increased. With adequate subcooling condensation-induced waterhammer occurred for initial liquid depths ranging from 25% to 95% of internal pipe diameter. The threshold mass flow rate of warm gas necessary to initiate waterhammer was greater as the initial liquid depth was lowered. For numerous tests with sufficient gas mass flow rate a condensation-induced shock occurred at the end cap of the test pipe, generating an acoustic (pressure) wave that propagated at a modified speed of sound toward the gas-liquid interface at the back of the slug. Peak shock pressures could be correlated with the gas mass flow rate for various initial liquid depth and suction pressures and temperatures. As the initial liquid temperature and pressure were increased the hydraulic shocks became lower because of smaller subcooling.

This paper describes the relationship between hydraulic losses and secondary flow within sinuous conduits with complicated bends. It has been found that the nature of secondary flow present in the bends is quite sensitive to the geometric configuration of the bend and the actual aspect ratio of the conduit section. Indeed, many different secondary flow patterns have been found to exist as the bend geometry is altered. A wide range of experiments has been conducted for various aspect ratios of a rectangular conduit with different curvatures.

Flow of a gas-liquid mixture in a piping system may be treated as a pseudo-fluid flow if the mixture is homogeneous and the void fraction is small. The governing equations for such flows are a set of nonlinear partial differential equations with pressure dependent coefficients. Shocks may be produced during transient state conditions. For numerical integration of these equations, two second-order explicit finite-difference schemes are introduced. To verify validity of the computed results, they are compared with the experimental results.

Careful experiments have been conducted for the purpose of investigating the phenomenon of condensation-induced waterhammer in an ammonia refrigeration system. To initiate a waterhammer event warm ammonia gas was introduced over static subcooled ammonia liquid placed in a horizontal 146.3 mm diameter carbon steel pipe 6.0 m in length. By means of fast response piezoelectric pressure transducers and a high speed data acquisition system rapid dynamic pressures were recorded whenever a shock event occurred. The occurrence of condensation-induced waterhammer depended upon three major variables; namely, (1) initial liquid depth, (2) liquid temperature, and (3) mass flow rate of warm gas. For given liquid depth and temperature, once the warm gas threshold conditions were exceeded shocks occurred with greater magnitude as the mass flow rate of gas input was increased. With adequate subcooling condensation-induced waterhammer occurred for initial liquid depths ranging from 25% to 95% of internal pipe diameter. The threshold mass flow rate of warm gas necessary to initiate waterhammer was greater as the initial liquid was lowered.Copyright © 2003 by ASME

The one-dimensional partial differential equations of mass and momentum are derived by applying control volume methods to an elastic conduit containing a compressible fluid. The derivation is accomplished by choosing a control surface to be represented by a differential element having cross sections (ends) fixed in space and wall boundary coincident with the pipe wall. By not including the pipe wall itself in the control volume the developed relationships do not directly include effects of the structure other than those of radial motion.

The one-dimensional equations of motion for a two-component mixture are expressed in conservation form. For numerical analyses, the equations are reduced to that of a one-dimensional homogeneous bubbly model which neglects any relative motion between the two phases. Hence, the three conservation relationships --conservation of the gas mass, of the liquid mass, and the mixture momentum --yield a set of differential equations that can be solved by various numerical methods. Comparison of the theoretical and measured speed of sound is made for both bubbly-and slug-flow. Finally, various numerical schemes are compared with existing experimental results in the literature.

For a large water pumping system with major surge protection devices, waterhammer analyses and site measurements have been conducted. Experiences have been obtained with respect to on-line and one-way surge tanks. The efficacy of these various surge protection devices has been assessed from site measurements. The large pumping system consisted of a 30-kilometer steel pipeline with four surge tanks and two one-way surge tanks. For this three-pump installation, measurements of pump speed, discharge valve position, pump flow rate, and pressure at seven locations were conducted under various transient test conditions. The site measurements under three-pump operation allowed for improvement of hydraulic transient calculations for future expansion to four and five pumps.

The rolling motion of a sphere on a smooth plane boundary in a simple-harmonic water motion has been analytically and experimentally investigated. For spheres having specific gravities ranging from 0·09 to 15·18 the sphere motion was found to be sinusoidal for both low and high values of the period parameter defined by Keulegan & Carpenter. The knowledge of the sphere motion, and hence the resultant force, allowed the determination of inertia and drag coefficients from Fourier-averaging techniques. Experiments in the inertial range yielded an added-mass coefficient of 1·2, compared with 0·67 from inviscid theory for translating spheres. For values of the period parameter greater than 30 the drag coefficient is reported to be approximately 0·74.

Two explicit numerical integration methods applied to the characteristics form of the St. Venant equations are investigated for the solution of transient supercritical open-channel flow problems. The characteristics-grid method which has been widely used for transient subcritical problems is found to be unworkable in the supercritical regime. The rectangular-grid method is found to be more useful, but becomes unstable for mesh spacings greater than 100 ft (30.5 m) and for flows exceeding the stability Froude number. Integration methods developed for subcritical transient simulation are therefore not readily and universally adaptable to the supercritical regime.

The formation and propagation of shock waves in a two-component flowing bubbly mixture has been investigated experimentally. The structure of shock waves formed by steepening of compression waves is compared with the corresponding features of shocks produced spontaneously in shock tubes. Experimentally determined values of the speed of propagation of the shock compare favorably with the Hugoniot relationship based upon a homogeneous two-phase model. The effect of the gravitational and frictional pressure gradients on the shock characteristics is also examined.

The diagnostic facilities of the cross power spectrum and the coherence function have been employed to enhance the identification of not only the inception of cavitation, but also its level. Two piezoelectric pressure transducers placed in the downstream chamber of a model spool valve undergoing various levels of cavitation allowed for the use of both functions—the phase angle of the complex cross spectrum and the dimensionless coherence function—to sense clearly the difference between noise levels associated with a noncavitating jet from those once cavitation inception is attained. The cavitation noise within the chamber exhibited quite a regular character in terms of the phase difference between instruments for limited cavitation. Varying cavitation levels clearly illustrated the effect of bubble size on the attendant frequency range for which there was an extremely high coherence or nearly perfect causality.

Vertically downward slug flow of air-water mixtures was experimentally investigated in circular pipes of diameter D = 2.60, 10.16, and 14.0 cm. The terminal velocity of descending, stationary, and ascending bubbles in downward flows was measured and correlated with the air and water volumetric flux densities. Except for very small pipe diameters, bubbles in downward flow are unstable and eccentrically located off the pipe axis in regions of lower fluid velocities. Consequently, the value of the flow distribution parameter C0 is less than unity for downward flow, compared to C0 = 1 for rising bubbles in quiescent liquid, and C0 = 1.2 for ascending bubbles in upward flow. Above a certain pipe diameter stable Taylor bubbles are not possible for downward flows. The terminal velocity coefficient C1 is no longer 0.35 for downward flows in relatively large pipes because the unstable bubbles ride the pipe wall, resulting in a higher value of C1.

The simple model of pressure pulse propagation in slug flow proposed by Henry, Grolmes, and Fauske has been extended by considering wave reflection and wave transmission at gas-liquid interfaces. A frequency-response model applied to a series of idealized gas and liquid slugs yields a pulse propagation speed that approaches the homogeneous model value as the number of slugs is increased for a given void fraction. All characteristic roots from the solution to a three-equation drift-flux model are related to the velocity of the center of mass of the mixture. The pulse propagation speed relative to this velocity is exactly equal to the homogeneous model value, however. Measured pulse propagation speeds in vertically downward slug flow are, as anticipated, much less than those predicted by the simple model of Henry, Grolmes, and Fauske, but slightly greater than the homogeneous model value. Measured pressure surges produced by the rapid closure of a downstream valve in a pipeline are reasonably well predicted by the drift-flux model. For the range of void fractions, pressures, and velocities encountered in this study, it is concluded that pressure pulse speeds and the magnitude of pressure surges in slug flow can be adequately predicted by a homogeneous model.

Two methods of analysis of surges in power canals, namely the graphical method of Bergeron and a finite-difference method based on the partial differential equations of motion, are applied to a surging situation of an engineering project for which laboratory model test results are available. For short power canals for which the effects of friction are small and the effect of gravity and inertial are significant a comparison of the results of the simple graphical method, for which bottom slope, boundary friction and finite-amplitude effects are neglected, with those of a finite-difference method, for which these effects are included, indicate that the graphical method of analysis is quite adequate for analyses of surging in short power canals.

The effective seepage force on cohesionless interfacial bed particles that comprise a plane bed was determined from the results of slope instability tests and from extrapolation of the results of erosion tests. The seepage flow was perpendicular to the bed and either into or out of the bed for the slope instability tests. Tests were conducted using two columns, one square and the other circular, in cross-section. For uniform sand particles ranging from 0.46 mm diam. to 0.72 mm diam., the seepage force on the interfacial sand grains was determined from slope instability tests to be one-half that on particles well within the bed. Subsequent to the condition of instability for seepage flow vertically upward and into a bed, erosion of the sand bed was measured. From an extrapolation of the results of the erosion tests to a condition of no erosion (which was assumed to correspond to the condition of incipient instability), it is concluded that the seepage force on the interfacial grains is approximately 35% to 40% of that on grains well within the bed.

A finite-difference method is applied to the gradually varied flow equations of open-channel flow for the purpose of simulating the gross aspects of bore propagation. In contrast to other treatments relating to bore inception and propagation the conservation equations of momentum and continuity across the bore are relaxed. The problems of dam break and the reflection of a bore from a dead end are solved and compared with the more exact solution based on the method of characteristics (Stoker’s solution). For both problems the results of the staggered-net finite-difference solution compare quite favorably with Stoker’s solution as long as the flow is subcritical. Although no sharp-fronted bore forms the surge represented by the gradually varied flow solution has the same maximum velocity and depth as the bore. The maximum depth and velocity behind the surge propagate at nearly the same velocity as the bore. The finite-difference solution provides as adequate simulation of such gross quantities of bore propagation as momentum and depth and velocity of flow.

THE EQUATIONS OF MOTION FOR UNSTEADY GRADUALLY-VARIED FLOW IN OPEN CHANNELS ARE EXPRESSED IN A FINITE-DIFFERENCE FORM SUITABLE FOR PROGRAMMING ON A HIGH-SPEED DIGITAL COMPUTER. THE STAGGERED-NET SCHEME INTRODUCED BY STOKER IS EXPANDED TO BE APPLICABLE TO A SYSTEM OF INTERCONNECTED CHANNELS, WITH EACH OF THEIR ENDS SUBJECT TO ONE OF THE FOLLOWING BOUNDARY CONDITIONS: DISCHARGE HYDROGRAPH, STAGE HYDROGRAPH, STAGE-DISCHARGE RELATIONSHIP, DEAD END OR JUNCTION OF CHANNELS. THE THEORY AND COMPUTER PROGRAM ARE TESTED AND COMPARED WITH EXISTING EXPERIMENTAL RESULTS CORRESPONDING TO THE FOLLOWING SITUATIONS: (1) FLOOD HYDROGRAPH IN CIRCULAR CHANNEL, (2) POWER-LOAD REJECTION IN HEADRACE OF TRAPEZOIDAL CANAL, (3) POWER-LOAD ACCEPTANCE IN TAILRACE OF RECTANGULAR MODEL CHANNEL, AND (4) TIDAL (STAGE HYDROGRAPH) IN RECTANGULAR MODEL ESTUARY. BECAUSE OF GOOD CORRELATION BETWEEN SIMULATED AND EXPERIMENTAL RESULTS IN ALL FOUR INSTANCES AND THE EASE OF CODING VARIOUS PROBLEMS, THE STAGGERED SCHEME OF STOKER IS STRONGLY RECOMMENDED FOR PRACTICING ENGINEERS. /ASCE/

Cavitation has been investigated in directional control valves in order to identify damage mechanisms characteristic of components of aircraft hydraulic systems. Tests have been conducted in a representative metal spool valve and in a model three times larger. Data taken under noncavitating conditions with both valves showed that the position of the high-velocity annular jet shifts orientation, depending upon valve opening and Reynolds number. By means of high-frequency response pressure transducers strategically placed in the valve chamber cavitation could be sensed by the correlation of noise with a cavitation index. The onset of cavitation can be detected by comparing energy spectra for a fixed valve opening and a constant discharge. Another sensitive indicator of cavitation inception is the ratio of cavitating to noncavitating spectral densities. The incipient cavitation number as defined in this investigation is correlated with the Reynolds number for both valves.