Joseph Cataldo

Professor of Civil Engineering


P.E. New Jersey and New York State

At Cooper, Dr. Cataldo teaches in the undergraduate and graduate civil engineering curricula in fluid mechanics and hydraulic engineering. He is also responsible for the development and operation of The Hydraulic Engineering Laboratory in the Civil Engineering department.

Dr. Cataldo has been conducting experiments on jet dynamics, the interaction of a jet and a wave, thermal plume behavior and oscillatory phenomena in Hydraulic Laboratory, as well as, infiltration studies in a semiarid and climate.

Dr. Cataldo has consulted on a number of outside environmental projects focused on the preservation of land and water resources. These include 1) the hydraulic and process design of sanitary treatment plants; 2) field and analytical study of leachate from a hazardous waste landfill; 3) hydraulic studies of the New York City Croton Water Shed; and 4) field studies on the Hudson River to determine the water quality and effect of thermal pollution. He is also an expert in the analysis of stream, estuary and ground water pollution.

At The Cooper Union faculty and student research go hand in hand. This has certainly been the case in the work that Dr. Cataldo and his students have conducted in the Fluids Laboratory. Over the years, the Fluids Laboratory has been the setting for research on jet dynamics under a surface wave—chaos—and entrainment flows; combined storm overflow in Jamaica Bay using stratified flow; monitoring petroleum contamination in an aquifer; and, the discharge of a thermal plume from a nuclear power plant.

The latter study was made possible by a grant he received from the National Science Foundation to create and study the thermal front phenomenon. He undertook studies involving the behavior of discharges from the Ginna Nuclear Power Plant into Lake Ontario. With additional support from Rochester Gas and Power, which operates the plant, Dr. Cataldo conducted field surveys that enabled him to take precise measurements of the thermal front phenomenon. He conducted insitu temperature and velocity measurements of the Ginna surface water thermal plume discharge while an aircraft equipped with a thermal mapper collected surface water infrared data. Clear oscillatory patterns were observed in the Lake’s thermal traces. He characterized these dynamic oscillations, or “thermal fronts,” as rapid internal temperature variations, which other researchers had also observed during their experiments on thermal discharge.

A physical hydraulic scaled model of the Ginna discharge was used to study the thermal front phenomenon and plume characteristics. An experimental study was conducted to characterize the origin and behavior of the thermal fronts. The Ginna fronts were first reproduced to ensure prototype conditions of actual fronts, with the discharge and ambient water conditions varied to determine the fronts’ behavior. The model was expanded with over 60 theristors and two hot film probes to measure temperature and velocity profiles.

A series of turbines with varying shapes have been installed in the Fluids Laboratory’s small flume. The shapes of these turbines vary from Francis type to the paddle wheel shape. A number of the flow parameters have been varied to better understand the power generating capacity of these turbines. The upstream velocity, water height, channel slope, and discharge have been adjusted for each turbine shape. Results indicate that the Francis turbine shows the most promise in generating power in this small channel.

Renewable energy experiments on oscillating flow have been conducted in the Fluids Laboratory. An apparatus has been built and shown to convert kinetic energy of a moving fluid stream into useful work by means of a cascade of thin airfoils positioned in the fluid stream. In one of the arrangements, the airfoils are provided with at least two degrees of freedom and adjacent airfoils are movable out of phase. The airfoils are subjected to the aerodynamically induced oscillations caused by the aero elastic phenomenon known as flutter and the oscillatory movement is then harnessed to do useful work. In an alternate system, a cascade of airfoils is mechanically oscillated within a moving fluid stream to increase the propulsion of the fluid. Where the fluid is a liquid, the cascade includes a cascade of hydrofoils.

A system of hydrofoils have been designed and tested in the Fluids Laboratory. These solid hydrofoils are vertical solid plates connected by a series of springs. By selecting the correct spring constants and plate dimensions, the system’s oscillations are observed. The reasons for the oscillation can be attributed to two actions and reactions occurring in a cyclic manner. These flows were determined using the Fluid Laboratory’s new two-dimensional Flowlite LDA system. Dr. Cataldo acquired this instrument in 2006 with a grant of $115,000 from the Major Instrumentation Program of the National Science Foundation.

Dr. Cataldo has been doing research on sustainable design of green roofs and greenstreets. He has developed a program to determine the thermal behavior of a green roof for a number of storms for varying seasons. He has been experimentally modeling green roofs in the laboratory under varying thermal and hydraulic conditions. Professor Cataldo is studying the hydrologic and hydraulic conditions on green streets in the Bronx and Queens to determine the effects of reducing CSO.

Dr. Cataldo has been conducting research on green streets in NYC. Four green streets have been monitored for climate and insitu temperature and hydrologic/hydraulic data collection. He has developed a model to predict the hydrology and hydraulic behavior of the different inlet and green street types.

Dr. Cataldo has received a grant to monitor the Javits Center Green Roof in NYC. This Green Roof is the second largest in the United States. It is approximately 7 acres in size and covers all of the impervious Javits Center roof. There is approximately $100,000 of monitoring equipment around, above and in the Green Roof. The study consists of the following:

Characterization of the microclimate of the Javits Center roof as well as the roofs of buildings located to the north, east, and south of it

                Expected outcomes:

  1. Quantification of the differences in air temperature, relative humidity, precipitation, wind speed and direction on the Javits Center before and after green roof installation
  2. Comparison of Javits center roof microclimate to surrounding rooftops before and after green roof installation
  3. Characterization of the extent to which the Javits Center green roof alters the microclimate on the roof, (with special focus on the portion of the roof that lies in close proximity to the rooftop mechanical equipment)
  4. Characterization of the extent to which the Javits Center green roof alters the microclimate on the rooftops of buildings in the surrounding neighborhoods (with special focus on how any observed microclimatological gradients relate to wind direction).

Characterization of the energy and water budgets of discreet sections of the green roof.

                Expected outcomes:

  1. Direct measurement of the volume and rate of runoff from the roof before and after green roof installation
  2. Direct measurement of the fraction of incident precipitation that is evapotranspired from the green roof surface
  3. Estimation of heat drawn off of the green roof vis-à-vis evapotranspiration processes
  4. Comparison of roof surface temperatures before and after green roof installation
  5. Direct measurement of the gradient in surface temperature between the roof surface and the ceiling of the Javits Center directly below it (before and after green roof installation)
  6. Continuous monitoring of the moisture content in the green roof growing medium to assess relationship between frequency and amount of precipitation, plant stress, and required irrigation frequency and amounts.

A graduate student has been using a model to determine the variation of the temperature through the Green Roof by using a USGS computer program VS2DT. The model simulates water and solute movement through variably saturated porous media. The advection-dispersion equation for single phase liquid water is used to describe energy transport. The finite difference method is applied to solve that equation.


 Javits Center 7 acre Green Roof









Professor Cataldo, Yoon Kim (CE graduate student) and Jozef Syta (CE senior undergraduate) working on the Photovoltaic cell that power the climate station


Major Publications:

Over 30 publications in major journals, the ASCE Power Division, Physics of Fluids, Review of Scientific Instruments, Plasma Physics, Fluid Dynamics Transactions, Journal of Fluids Engineering, ASME, The Open Hydrology Journal.

Professor Cataldo has been awarded the 1999, 2006, and 2007 Chi Epsilon Excellence in Teaching. He has advised approximately three dozen Master Dissertations