practical field technique for measuring reservoir evaporation utilizing mass-transfer theory by Guy Earl Harbeck Download PDF EPUB FB2
STUDIES OF EVAPORATION A PRACTICAL FIELD TECHNIQUE FOR MEASURING RESERVOIR EVAPORATION UTILIZING MASS-TRANSFER THEORY By G. EABL HAEBECK, JR. ABSTRACT Studies of evaporation made in recent years nave provided values of the mass-transfer coefficient, N, in Cited by: Studies of evaporation made in recent years nave provided values of the mass-transfer coefficient, N, in the equation E=Nut(e0—ea) for reservoirs having surface areas ranging from 1 to nea acres.
The apparent correlation of N with reservoir surface area may in large part be associated with variations in the shape of the wind profile near the surface resulting from differences in.
|a A practical field technique for measuring reservoir evaporation utilizing mass-transfer theory / |c by G. Earl Harbeck, Jr. 1 |a Washington: |b United States Department of the Interior, Geological Survey, |c |a 1 online resource (9 unnumbered pages): |b illustrations. Add tags for "A practical field technique for measuring reservoir evaporation utilizing mass-transfer theory: evaporation from many reservoirs can be computed from records of reservoir stage, wind speed, humidity, and water-surface temperature".
Be the first. INTRODUCTION • Evaporation is rarely measured directly • Estimating methods include: – pan coeffi i tfficient x measured pan evaporation – water balance – energy balance – mass transfer – combination techniques • Emphasis will be practical methods 12‐Mar‐ ET Workshop 2.
A pr actical field technique for measuring reservoir e vaporation utilizing. mass-transfer theory. Moreover, the proposed model is compared by measurement evaporation and the following models.
evaporation, water balance, energy balance, mass transfer, and combination techniques. The selection of the "best" technique to use for a particular computation is largely a function of the data availability, type or size of the water body, and the required accuracy of the estimated evaporation.
|'E) A practical field technique for measuring reservoir evaporation utilizing mass-transfer theory, by G. Earl Harbeck, Practical field technique for measuring reservoir evaporation utilizing mass-transfer theory book T) Methods to compute long-wave radiation from the atmosphere and reflected solar radiation from a water surface, by.
A Practical Field Technique For Measuring Reservoir Evaporation Utilizing Mass-Transfer Theory. Article. Modeling of evaporation from the reservoir is crucial for water management at the area.
to approximate the evaporation from each dam, the ET O for each dam reservoir was gathered from the map of Reference Evapotranspiration, using the coordinates of each dam (see Section 5).
The evaporation of each dam reservoir was calculated by using Equation 56 of FAO () as follows: ET c = K c x ET O [Equation 1] Where: ET c. G.E. HarbeckA practical field technique for measuring reservoir evaporation utilizing mass-transfer theory U.S. Geol. Survey Prof. Pap., E (), pp.
Google Scholar. Taylor, Hamon, Jensen-Haise, Mayer and Rohver methods was used to estimate the evaporation from the Dez reservoir. These methods are divided into four categories: 1.
Methods based on energy budget 2. Methods based on mass transfer 3. Methods based on radiation and temperature and 4. Combination of energy budget and mass transfer. placement affects measurements. The energy budget of the reservoir was calculated using temperature profiles.
Simpler methods are available for practitioners seeking to measure reservoir evaporation. For practical purposes, reservoir evaporation rates are commonly determined with evaporation pans, or calculated from weather station data.
Mass transfer method Evaporation driven by – Vapor pressure gradient –Wndi speed e s: saturation vapor pressure at temperature above surface e a: vapor pressure at some level above surface u: wind speed at some level above surface a,b: empirical constants (a bu)(e e) E f(u)(e e) s a s a = + − = −.
Earlier studies (Singh and Xu, ; Xu and Singh,) have evaluated and compared various popular empirical evapotranspiration equations that belonged to three categories:(1) mass-transfer based methods, (2) radiation based methods, and(3) temperature-based methods; and the best and worst equations of each category were determined for the study regions.
In this study a cross. Measuring evaporation from soil surfaces for environmental and geotechnical purposes and field measurements. The paper is intended to be both informative and a practical guide to measuring evaporation in the fie ld. the technique to engineers for their practical use, and to demonstrate its capabilities and deficiencies and its potential.
Estimates of daily mean evaporation rates (blue line) from a buoy (inset) at Lake Tahoe in using a mass transfer approach with measurements of surface water temperature, air temperature, vapor pressure, and wind speed collected at the NASA JPL buoy. Shown is the day running-mean evaporation rate (red line).
Moninin-Obukhov Similarity (MOS) Theory using an iterative technique was used to estimate EBR evaporation rates. For verification of the MOS technique, the results were compared to measured evaporation using both the eddy- covariance and bulk-aerodynamic methods.
Results were compared for a period of measurement from June through December of Tanny et al. () used an ECS to directly measure evaporation from a small settling reservoir at the Eshkol site in northern Israel.
There, the water level and consequently the sensor’s height above the water surface were constant throughout the measurement per-iod. The fetch within the reservoir for the ECS, located at the reser.
The apparent correlation of N with reservoir surface area may in large part be associated with variations in the shape of the wind profile near the surface resulting from differences in and analysis.
application/pdf /ppE en A practical field technique for measuring reservoir evaporation utilizing mass-transfer theory. The enhancement of heat and mass transfer using a static electric field is an interesting process for industrial applications due to its low energy consumption and potentially high level of evaporation rate enhancement.
However, to date, this phenomenon is still not understood in the context of the evaporation of sessile drops. extraction, leaching, distillation, humidification, drying and evaporation. Objectives: To give the students a application of diffusion theory to simple mass transfer problems.
Analysis of chemical engineering unit operations involving mass transfer. Design principles for mass transfer equipment. Solids/Liquids separation processes. The ratio between daily pan and EC evaporation varied from to The bulk mass transfer coefﬁcient was estimated using a model based on measurements of water surface temperature, evaporation rate and absolute humidity at and m above the water surface, and using two theoretical approaches.
The bulk transfer coefﬁcient. A continuous flow measurement recorder is provided for making water flow measurements in an open channel. An ultrasonic sensor obtains pressure head measurements upstream from a flume or weir located in the open channel.
A central processing unit receives the head measurements from the sensor and calculates the water flow rate and the total flow. The evaporation from the surface can be calculated as. g s = ( kg/m 2 h) ( m 2) (( kg/kg) - (kg/kg)) / = kg/s. The evaporation heat (enthalpy) of water at temperature at 20 o C is kJ/kg.
The heat supply required to maintain the temperature of the water in the swimming pool can be calculated as. q = ( kJ. fluids present in the reservoir, estimate well productivity, current reservoir pressure, permeability, and wellbore conditions from mathematical flow equations and dynamic pressure buildup measurements.
The technique requires that a well be produced for a period of time and then shut-in for an appropriate length of time. Analysis inputs Figure evaporation from a pan, the seasonal variation in pan coefficients make this technique questionable, if used to measure reductions in evaporation for short periods, such as a week or month.
Other techniques for computing evaporation include the energy-budget and mass-transfer techniques. Mass Transfer traditionally follows and builds upon that of (and not upon Fluid Heat Transfer. Mechanics). In fact, development in mass-transfer theory closely follows that in heat transfer, with the pioneering works of Lewis and Whitman in (already proposing a mass-transfer coefficient.
h m similar to the thermal convection coefficient h. The heat storage changes (Q t) can be a significant component of the energy balance in lakes, and it is important to account for Q t for reasonable estimation of evaporation at monthly and finer timescales if the energy balance-based evaporation models are r, Q t has been often neglected in many studies due to the lack of required water temperature data.
Determination of evaporation from lake and reservoir surfaces using the heat balance method T. Kirillova, T.
Ogneva and L. Nesina Abstract. The paper presents some results of a study, carried out ai the Main Geophysical Observatory, on the development of methods for determining evaporation from lake and reservoir surfaces.
in terms of physical regularities of evaporation using meteorological and geophysical data as ancillary values. The methods are commonly referred to as turbulent diffusion or mass transfer methods.
A great number of evaporation devices of various types were used in experimental studies of evaporation or evapotranspiration.Measuring Forest Evapotranspiration-Theory and Practice.
USDA Forest Service Research Paper NE, U. S. Department of Agriculture, Washington, D.C. Iarbeck, Jr., G. E. A Practical Field Technique for Measuring Reservoir Evaporation Utilizing Mass-Transfer Theory.evaporation H NkT o Ea kT 3 2 1 2 // J P kTm 2 2 R m k P T Area d r evaporation 24 22 For evaporation, the vapor pressure is, where is the surface tension of the liquid, N is avagadro’s number, and H is the enthalpy of evaporation (the energy required to convert from a liquid to gas phase).