Robert Meroney | Colorado State University (original) (raw)

Papers by Robert Meroney

Journal of Wind Engineering and Industrial Aerodynamics, 1988

ABSTRACT Discussion of Session 5: Low-rise structures, Q&A between audience and speakers.

Plant/Operations Progress, 1992

ABSTRACT An expert panel examined the influence of complex terrain, industrial plant obstacles an... more ABSTRACT An expert panel examined the influence of complex terrain, industrial plant obstacles and thermal inhomogeneities on the dispersion of gaseous plumes or aerosols resulting from accidental releases of hazardous materials. Perturbations in transport and dispersion induced by such flow disturbances were estimated. The limitations and accuracies of current numerical and physical modeling techniques were examined. Finally, important unresolved questions concerning the estimation of transport of hazardous materials in the presence of realistic industrial building, storage and transportation environments were identified.

Journal of Wind Engineering and Industrial Aerodynamics, 1993

A large eddy simulation of a microburst producing thunderstorm is carried out. The thunderstorm i... more A large eddy simulation of a microburst producing thunderstorm is carried out. The thunderstorm is initiated when a thermal within a developing mixed layer reaches the lifting condensation level and strong latent heating occurs. A microburst is subsequently produced as condensate from the thunderstorm falls beneath the melting level. In this study, the viability of using two-way interactive multiplenested grids to investigate the interaction of the outflow from the microburst with a much smaller scale architectural structure is investigated. The relationship of the fluctuating winds around the building to the microburst structure is described.

Atmospheric Environment, 1994

Most of the critical transport processes in the atmosphere are dominated by density stratificatio... more Most of the critical transport processes in the atmosphere are dominated by density stratification; hence, physical modeling facilities which neglect the important contributions of buoyancy are limited to the examination of high winds or those brief moments after sunrise or before sunset when the atmosphere is nominally neutrally stratified. Large new facilities constructed specifically to simulate the atmosphere offer new opportunities to study the physics of mixing processes dominated by stratification. A novel arrangement to simulate stably stratified atmospheric boundary layer flows in large wind tunnels using distributed electrical heaters and an inverted ground plane to simulate nighttime inversions is described, together with initial measurements.

Transportation Engineering Journal of ASCE

A review and critical assessment of wind prospecting methodologies is presented. It is shown that... more A review and critical assessment of wind prospecting methodologies is presented. It is shown that: (1) the production of equivalent wind speed data near ground level (less than 100 m) requires accurate reproduction of surface roughness, shape, and vegetation. While adequate for certain dispersion simulations, terraced models are not appropriate for wind turbine site selection; (2) current meteorological data in complex terrain is not yet adequate as a supplier of inflow conditions for either numerical or physical models; and (3) physical modeling was able to reproduce the relative wind speeds found over complex terrain, by rank, to sample correlation coefficient levels of 0.79-0.95, day-to-day quantitative wind speeds to 0.70-0.76, wind speeds to 0.81, and day-to-day site wind directions to 0.65-0.67.

This report was prepared as an account of work sponsored by an agency of the United States Govern... more This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use or the results of such use of any information, apparatus, product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights. 11 EXECUTIVE SUMMARY Oahua Island, Hawaii, is known to possess a rich windpower resource due to the prevailing trade wind boundary layer. Several Wind Energy Conversion System (WECS) installations have been proposed for the Kahuku Point region. Although limited field measurements have now been performed at certain proposed sites, other wind power sites or regions may exist which might have greater local potential. The present study of wind tunnel tests over a Kahuku Point model is to extend the value of field results and to provide detailed information for WECS installations in this region. Field measurements were used to validate the windtunnel results at several selected sites. A contoured model of the Kahuku Point area was prepared to an undistorted scale of 1:3840. Local terrain roughness due to topography features was simulated. The approach flow over the model was adjusted to match a typical marine trade wind boundary layer. For three different wind directions, which encompass the predominate directions from which the Pacific trade wind blows over the Kahuku Point region, measurements of wind speed and turbulence at proposed WECS sites and 40 additional grid locations were performed. These measurements were used to produce horizontal contour plots of relative wind power. After careful examination of field measurement and wind tunnel test conditions, nineteen comparable data pairs were identified. The linear correlation between field and laboratory measurements of these data pairs was found to be 0.71. A correlation by rank of relative wind speed for these data pairs revealed a simulation at a level of 0.84. To evaluate several currently proposed methods for speed-up prediction of flow over hills, one semi-empirical and one analytical technique were applied to several selected WECS sites. Comparison with the laboratory results indicates that both methods predict values which braket typical topography amplification. Improvement in prediction of the approach flow appears to be the first step in reducing the uncertainty of the speed-up prediction.

Recent studies have revealed the high potential for agriculture applications of wind energy syste... more Recent studies have revealed the high potential for agriculture applications of wind energy systems in the United States. The dairy farm is one of the enterprises identified as feasible for wind energy application. To make wind energy application in dairy operations economically feasible, the design and selection of dairy farm wind generator systems should meet specific dairy needs. Forty to 75 percent of the electrical energy consumed in the dairy farm goes into the cooling of milk and heating of water to meet the 3-A milk standards. Wind energy substitution for utility power to meet these energy needs in milk production operations is an efficient application of wind energy. To make wind energy substitution for utility power economically feasible, accurate design of the wind energy system to match the dairy energy demand, and the utilization of energy saving devices to reduce the dairy energy demand are essential. This report develops a model which determines the minimum milk cooling and water heating energy demands for different lactating dairy herd sizes relative to the parlor size. The model then identifies and selects the least cost wind energy system which meets the dairy milk cooling and water heating energy demand for a wide range of herd sizes, at four levels of energy conservation under various wind regimes.

Mean velocity and turbulent intensity profile Velocity profile in the lateral direction of the TS... more Mean velocity and turbulent intensity profile Velocity profile in the lateral direction of the TSWT Calibration curve of mean concentration measurements. Flow visualization photographs using helium bubble technique (top view)(z = H/2

This study investigates the fluid-modeling techniques used to simulate wind-forced natural ventil... more This study investigates the fluid-modeling techniques used to simulate wind-forced natural ventilation rates of rectangular, single-cell low-rise buildings. A 1:25 scale model of the Texas Tech University Wind Engineering Research Field Laboratory is used in a boundary-layer wind tunnel to evaluate alternative strategies for simulating infiltration into permeable buildings. A new approach is proposed which should permit evaluation of a wide range of leakage situations. In addition data is used to critique standard full-scale tracer gas test methods.

Physical simulation of a series of four, six cubic meter Liquefied Natural Gas (LNG) spills on wa... more Physical simulation of a series of four, six cubic meter Liquefied Natural Gas (LNG) spills on water was provided by the Meteorological Wind Tunnel facilities at Colorado State University. Field data were collected from spills performed at Naval Weapons Center, China Lake, California, in Fall 1978. The simulation test series was to provide field test planning information, extend the value of a limited set of field measurements, and validate the concept of physical modeling of LNG plume dispersion as a predictive hazard analysis tool. Two test series were conducted to aid in placement of field concentration measurement instrumentation. The first utilized 1:170 scale model of the China Lake site in the Meteorological Wind Tunnel and the second utilized 1:85 scale model in the Environmental Wind Tunnel. Dispersion data collected in the four field tests at China Lake were extended in two test series conducted in the Environmental Wind Tunnel over a 1:85 scale model. The following result...

Water spray curtains can provide an effective and rapid dilution mechanism for low lying dense cl... more Water spray curtains can provide an effective and rapid dilution mechanism for low lying dense clouds. Frequently such clouds are released as a result of a chemical manufacturing, storage or gas transportation accident. Gases of concern include cold liquefied natural gas (LNG), refrigerated rocket propellants or oxidants, agricultural chemicals (ammonia), gaseous fuels (propane) or other high-molecular weight gases (fluorinated hydrocarbons). Since for most atmospheric conditions the dense gases will remain negatively buoyant for significant time intervals, a ground-level hazard may exist due to gas flammability or toxicity. Extensive field and laboratory tests have been performed to determine how well water curtains can mitigate actual spill conditions (Blewitt et al, 1987; Heskestad et al., 1983; Meroney et al., 1984; Moodie et al., 1981). Numerical methods are often proposed to provide system design or timely response information (Meroney, 1984a, 1984b, 1985, 1989, 1991; Meroney ...

Wind tunnel studies of optimum sites for wind power turbines were made. A systematic evaluation o... more Wind tunnel studies of optimum sites for wind power turbines were made. A systematic evaluation of the flow over two-dimensional ridges is reported. Two-dimensional ridges with definite crests, such as ideal triangular or sinusoidal shapes, produce the greatest amplifications in local wind speed. Bluff, very steep and flat topped ridges do not produce as large an increase in velocity as the crest ridges. The ridges tested were of small characteristic size compared to the boundary layer thickne.ss. The models correspond to ridges of the order of 100 meters or less in the atmosphere. For these ridges it is found that local viscous effects are of second order and the speedup of velocity can be predicted by inviscid flow considerations. Only near the surface (corresponding to approximately one to two ridge heights) are large changes in velocity observed. Wind velocity increases of the order of two times or greater than that of the approach velocity are measured at the crest of the triangular ridge. A slope of 1 to 4 (14 degrees) for the triangular ridge gives the optimum speedup at the crest. The flow in the outer region of the boundary layers over the ridge was found to remain similar to the flow upstream of the ridge. The longitudinal turbulent velocity component was found to decrease slig:• ,tly near the ridge surface as the flow progressed over the windward face of the ridge. The vertical turbulent velocity component increased slightly along the windward face of the• ridge. The variation in turbulent velocities over the windward face of the ridge correspond to effect of a contraction on isotropic turbulence. 4 SITES FOR WIND-POWER INSTALLATIONS Wind Tunnel Simulation of the Influence of Two-Dimensional Ridges on Wind Speed and Turbulence ' •~

Boundary-Layer Meteorology, 1997

... Figure 2b. Vertical profiles of the mean temperature . Page 6. 144 YUJI OHYA ET AL. Figure 3a... more ... Figure 2b. Vertical profiles of the mean temperature . Page 6. 144 YUJI OHYA ET AL. Figure 3a. Vertical profiles of the turbulent intensities (rms values), u-component velocity u0; dashed line,Arya (1975), Ri = 0.1; dash/dotted line, Ogawa et al. (1982), Ri = 0.57. ...

Journal of Applied Meteorology, 1981

Wind and Structures, 2001

The objective of this study is to understand the flow above the front edge of low-rise building r... more The objective of this study is to understand the flow above the front edge of low-rise building roofs. The greatest suction on the building is known to occur at this location as a result of the formation of conical vortices in the separated flow zone. It is expected that the relationship between this suction and upstream flow conditions can be better understood through the analysis of the vortex flow mechanism. Experimental measurements were used, along with predictions from numerical simulations of delta wing vortex flows, to develop a model of the pressure field within and beneath the conical vortex. The model accounts for the change in vortex suction with wind angle, and includes a parameter indicating the strength of the vortex. The model can be applied to both mean and time dependent surface pressures, and is validated in a companion paper.

Wind and Structures, 2002

ABSTRACT

Atmospheric Processes over Complex Terrain, 1990

Physical modeling studies of atmospheric flow over hills and mountains span 60 years of research ... more Physical modeling studies of atmospheric flow over hills and mountains span 60 years of research in more than seven countries. Early work in the 1920s led to evaluation of air currents around the Rock of Gibraltar for airfield safety. Water channel work by Long in the 1950s examined lee-wave development over the Sierra Nevada of California. During the 1970s and 1980s laboratory measurements examined speedup over idealized two- and three-dimensional hills and escarpments for wind-power climatology purposes. Since the mid-1960s many fluid-model tests have examined transport and dispersion of pollutants over complex terrain. Considered together there is a wealth of information about the influence of hills and mountains on streamline patterns, speedup, turbulence, and separation under many topographic and atmospheric conditions. This chapter will consider the advantages and limitations of physical modeling, review the principle conclusions drawn through physical modeling, and suggest experiments that might result in a better understanding of the flow processes over complex terrain.