A modified wetted-wall cyclone using different methods of water injection techniques upstream of the inlet was designed as an improvement to a wetted-wall cyclone developed by White, which uses liquid injection through a port on the wall of the cyclone inlet. The new cyclone has a high aerosol sampling flow rate (1250 L/min) and maintains constant cut-point with the modified White-type cyclone along with greater collection efficiency, lower time response, and reduced pressure drop. The final air-blast atomizer cyclone (AAC2.1a) design considered has an aerosol-tohydrosol collection efficiency cut-point of 1.3 mm with collection efficiencies at 1 and 2 mm of 39.9% and 86%, respectively. The efficiency reported for the modified White-type cyclone for particle sizes of 1 and 2 mm was 40.5% and 76.3%, respectively, under no water bypass conditions. The aerosol-to-aerosol transmission efficiency for the AAC2.1a configuration was found to be approximately 53.7% for 1 mm diameter particles as compared with 67.2% for the modified White-type cyclone. Dry and wet time response tests were performed in which the modified White-type cyclone had an initial response of 2.5 minutes for a wet start and 1 minute for a dry start for a condition where there was no liquid carryover through the cyclone outlet. The rise time for AAC2.1a cyclone under dry and wet start conditions was 0.5 minutes and 1.3 minutes, respectively. The decay response of the modified White-type cyclone was 1.1 minutes for a wet start and 1.2 minutes for a dry start. The corresponding numbers for AAC2.1a cyclone were 1.4 minutes for a dry start and 1 minute for a wet start condition. Off design tests were run at approximately ±10% air flow rates to see the effect on cyclone performance. It was seen that at a 10% higher flow rate (1350 L/min) the efficiency was 54.3%. At a 10% lower flow rate (1125 L/min) the efficiency was 33.7% as compared with an efficiency of 39.9% at 1250 L/min for 1.0 mm PSL particles. It was found that at a water input of 0.8 mL/min the efficiency reduced to 79.3% as compared to 86% at an input flow rate of 1.6 mL/min for 2 mm size PSL.

To ensure effective detection of bio-particles, it is crucial to understand the effects of collection method and archiving conditions on the survivability of bioaerosols, consequently, the survivability of the spore-forming Bacillus globigii (BG) and MG1655 Escherichia coli (E. coli), was determined after collection. The survivability was defined as the culturable fraction of the archived bacteria/culturable fraction of the as-collected bacteria. The bacteria were aerosolized for up to four days at room temperature (RT, 25 degrees C) and at 4 degrees C and collected in a 100 L/min wetted wall cyclone (WWC) and a 12.5 L/min SKC BioSampler. Aqueous solutions of 0.01% Tween-20 and 30% Ethylene Glycol (EG), with or without 0.5% ovalbumin (OA), were used as the collection fluids. Antifoam B (A-F), at a concentration of 0.2% (V:V) was added to the BG samples containing OA. In general, samples archived at 4 degrees C showed higher survivability than at RT. The survivability were more stable in EG than in Tween-20 especially for BG, very likely due to the surfactant effect of the Tween-20, which would remove the spore coat and initiate germination. In the WWC, adding OA significantly increased the survivability of BG in EG and in Tween-20, especially at RT. Similar effect of OA was found for E. coli samples stored in EG, suggesting that OA might be beneficial in maintaining the survivability. Adding A-F increased the survivability of BG in EG. In the SKC, neither the addition of OA nor A-F seems to have a beneficial effect on the survivability of the spores in EG samples. The best collection fluid for maintaining survivability in the WWC is EG+A-F for BG, and EG+OA for E. coli. However, in the SKC, EG is the best for BG collection and Tween-20 for E. coli. Viability transfer ratios, VTR, (cells surviving collection at time zero/viable cells aerosolized) were calculated for both devices. A performance ratio was calculated as the VTR of the WWC/VTR of the SKC. The geometric mean of the performance ratio is 1.51+/-0.83 for BG and 2.60+/-0.16 for E. coli, indicating that viability transfer ratio of the WWC is typically higher than that of the SKC.

In this study, a system for the collection of bioaerosols emitted from the mail sorting process was designed and characterized. Two different wetted-wall cyclones, the JBPDS cyclone and the glass cyclone sampler (GCS), were evaluated as system collection devices. These devices operate at 780 L/min and have a D50 of ~ 1 μm. A trimming impactor with a D50 of 10 μm was used upstream of the collection devices. Using two reference probes, the cyclone liquid outputs were compared with aerosol collected on filters and the output of an Aerosol-to-Hydrosol Transfer Stage (AHTS). The mass emission rate of the postal sorting machine was 3.15 mg/min and found not to vary significantly with flow rates above 700 L/min. On average, greater than 66% of the mass collected had a Da < 10 μm. Using a Coulter Counter, the volume median diameter (volume equivalent) for both device hydrosol outputs was 4.18 μm. For the effluent aerosol, the volume median diameter was 12.5 μm. For a bioaerosol release, this study found that greater than 65% (by volume) of the material released had a Da greater than 7.2 μm. Using filters, it was found that on average, 95% of the bioaerosol particles emitted had a Da less than 10 μm. According to the reference data, the expected number of bioaerosol particles in 1.5 times that collected by the GCS and 5.5 times that collected by the JBPDS cyclone for a one milligram release. The time constant for the system in response to a letter release was found to be 1.3 minutes for the GCS and 1.75 minutes for the JBPDS cyclone. A final note to this study states that the probe dimensions were incorrectly developed, therefore affecting the aspiration efficiency of the probes. In turn, this may have affected the outcome of some of the results. A plot is given at the end of the paper showing to what extent the results may have been affected. It is recommended that further experimental studies be performed to verify the results in this study.

This work includes wetted wall column experiments that measure the CO₂ equilibrium partial pressure and liquid film mass transfer coefficient (kg') in 7, 9, 11, and 13 m MEA and 2, 5, 8, and 12 m PZ solutions. A 7 m MEA/2 m PZ blend was also examined. Absorption and desorption experiments were performed at 40, 60, 80, and 100°C over a range of CO₂ loading. Diaphragm diffusion cell experiments were performed with CO₂ loaded MEA and PZ solutions to characterize diffusion behavior. All experimental results have been compared to available literature data and match well. MEA and PZ spreadsheet models were created to explain observed rate behavior using the wetted wall column rate data and available literature data. The resulting liquid film mass transfer coefficient expressions use termolecular (base catalysis) kinetics and activity-based rate expressions. The kg' expressions accurately represent rate behavior over the very wide range of experimental conditions. The models fully explain rate effects with changes in amine concentration, temperature, and CO₂ loading. These models allow for rate behavior to be predicted at any set of conditions as long as the parameters in the kg' expressions can be accurately estimated. An Aspen Plus® RateSep™ model for MEA was created to model CO₂ flux in the wetted wall column. The model accurately calculated CO₂ flux over the wide range of experimental conditions but included a systematic error with MEA concentration. The systematic error resulted from an inability to represent the activity coefficient of MEA properly. Due to this limitation, the RateSep™ model will be most accurate when finetuned to one specific amine concentration. This Aspen Plus® RateSep™ model allows for scale up to industrial conditions to examine absorber or stripper performance. / text

A viscous/inviscid interaction method for predicting the effect of viscosity on the performance of wetted and cavitating propulsors is presented. The emphasis is placed on steady wetted and cavitating propulsor flows. A three-dimensional low order potential based boundary element method is strongly coupled with a two dimensional integral boundary layer analysis method based on the strip theory assumption. The influence of viscosity on the outer inviscid flow is modeled through the wall transpiration model by distributing “blowing” sources on the propulsor blade and trailing wake surfaces. The boundary layer edge velocities are expressed as the sum of the inviscid edge velocity and a correction which depends only on the boundary layer variables. The influence of outer potential flow on the inner boundary layer flow is considered through the edge velocities. In the case of sheet cavitation, a “thin” cavity approach is employed and the viscous/inviscid interaction method is applied on the blade surface underneath the cavity. On the cavity surface, the friction force coefficient is forced to be zero. Numerical predictions by the present viscous/inviscid interaction method are presented for open, ducted, and water-jet propulsors. For water-jet propulsors, the flow is solved in an iterative manner by solving the rotor and stator problems separately and by considering the time-averaged effects of one component on the other. Predicted forces, pressure distributions, and boundary layer variables are compared with those predicted by other numerical methods and experimental measurements. / text

Heterogeneities in fractured rock are found at all scales; from the scale of individual fractures, to the scale of fracture networks, and to the largest regional scales. These heterogeneities cause challenges for modelling and parameter estimation of flow and solute transport. The heterogeneities in fracture aperture, characterization of the flow channelling they are causing, and implementation of this information into numerical simulation models of the solute transport in fractured media are the subjects of this thesis. Aperture variability within a fracture causes the flow channelling, where the water flow is focused in a few channels and other areas of the fracture have practically stagnant water. The flow-wetted surface is the area where the flowing water is in contact to the fracture area. Contaminants are transported with the flowing water and therefore the flow-wetted surface is an important parameter that influences the diffusion into the rock matrix and sorption to the fracture rock surface. The specific flow-wetted surface (sFWS) is the flow-wetted surface divided by the total fracture area. The sFWS is systematically analyzed for different fracture aperture distribution characteristics. The local aperture is linked to the local hydraulic conductivity K. Increasing standard deviation of the hydraulic conductivity K field (σln K) leads to decreased sFWS. The sFWS is found to be independent of the correlation length (λ) of the field. An empirical relationship is developed, which describes the sFWS as a function of the σln K. A method is also introduced to determine this key parameter by analysis of the breakthrough curve from a single-well injection-withdrawal (SWIW) test. Further, an approach is presented to incorporate the effect of fracture level heterogeneity into fracture network models and to analyze the effect on sorption and matrix diffusion, by including the sFWS parameter into the transport calculations. The results show that the median transport time is proportional to the square of the sFWS-value. The results also suggest that there are an averaging behaviour in the fracture network, the sFWS-value of each individual fracture is not important for the transport over the domain, but a mean-value can be utilized in the numerical model. / Heterogeniteter i sprickigt berg finns i alla skalor, från millimeterskala till en skala på hundratals kilometer. Dessa heterogeniteter orsakar problem vid beräkning av vattenflöde och ämnestransport. Aperturen i en spricka är öppningen mellan de två omslutande bergsidorna, den varierar både inom och mellan olika sprickor. Ämnet för denna avhandling är heterogeniteter i aperturerna inom enskilda sprickor, karaktärisering av den flödeskanalisering som uppstår på grund av dessa heterogeniteter och hur man kan använda denna information till en numerisk modell.Variabilitet av aperturen i en enskild spricka gör att vattenflödet blir fokuserat i ett fåtal kanaler, medan andra områden av sprickan kan ha praktiskt taget stillastående vatten. Den flödesvätta ytan är det område där det strömmande vattnet kommer i kontakt med sprickytan. Den flödesvätta ytan som påverkar diffusionen in i bergmatrisen och sorptionen till sprickytan är en viktig parameter eftersom föroreningar transporteras med det strömmande vattnet. Den specifika flödesvätta ytan (sFWS) är den flödesvätta ytan dividerad med den totala sprickarean. I avhandlingen analyserades sFWS systematiskt för olika statistik över sprickaperturen. Den lokala aperturen är kopplad till den lokala hydrauliska konduktiviteten K. En ökad standardavvikelse för det hydrauliska konduktivitetsfältet (σln K) ledde till minskad sFWS. sFWS visades vara oberoende av konduktivitetsfältets korrelationslängd (λ). En empirisk relation utvecklades som beskriver sFWS som en funktion av σln K. Ett SWIW-test är en typ av spårämnesförsök, där ett spårämne injiceras i en brunn följt av vatten i en bestämd tidsperiod, innan flödet vänds och en genombrottskurva registreras. Testet används traditionellt för att bestämma bergets diffusions- och sorptionsegenskaper. En metod presenterades för att bestämma den specifika flödesvätta ytan genom analys av genombrottskurvan för ett SWIW-test. Ett tillvägagångssätt introducerades för att analysera effekterna av sorption och matrisdiffusion i heterogena sprickor i en spricknätverksmodell genom att inkludera sFWS-parametern i transportberäkningar. Resultaten visade att medianvärdet för transporttiden är proportionell mot kvadraten på sFWS-värdet. Resultaten visade också att transporten genom spricknätverket inte är beroende av sFWS-värdet i de individuella sprickorna, utan att medelvärdet kan användas för modellering.

Submitted by RICARDO AUGUSTO DECARO (ricardodecaro@gmail.com) on 2018-04-15T18:32:57Z No. of bitstreams: 1 Dissertação - Ricardo Decaro.pdf: 1699292 bytes, checksum: 5156a46add5be4895637eb3ef40de04b (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-16T10:45:39Z (GMT) No. of bitstreams: 1 decaro_ra_me_jabo.pdf: 1699292 bytes, checksum: 5156a46add5be4895637eb3ef40de04b (MD5) / Made available in DSpace on 2018-04-16T10:45:39Z (GMT). No. of bitstreams: 1 decaro_ra_me_jabo.pdf: 1699292 bytes, checksum: 5156a46add5be4895637eb3ef40de04b (MD5) Previous issue date: 2018-04-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os estudos e pesquisas em Tecnologia de Aplicação são importantes para aperfeiçoar a aplicação de caldas no Brasil e no mundo. Conhecer o efeito de caldas contendo diferentes produtos fitossanitários e adjuvantes em relação a diferentes superfícies vegetais é muito importante para posicionar as melhores combinações de caldas, visando promover assim, o efeito desejado da gota no alvo. Desta forma, o presente trabalho teve como objetivo avaliar o espalhamento de gotas de caldas fitossanitárias contendo dois fungicidas amplamente usados na agricultura em associação com adjuvantes, além de água, sobre diferentes superfícies vegetais. Foram realizados experimentos para avaliações de tensão superficial, ângulo de contato, área molhada pela gota e espectro do tamanho de gotas produzidas pela ponta XR 11002 das diferentes caldas fitossanitárias. As superfícies analisadas foram folhas de citros, café, milho, soja, algodão, cana, vidro e parafilme. O delineamento foi inteiramente ao acaso no esquema fatorial 2 (fungicidas) x 5 (adjuvantes) + 1 (água) para as variáveis tensão superficial e espectro de tamanho de gotas e 2(fungicidas) x 2 (superfícies abaxiais e adaxiais) x 5 (adjuvantes) + 1 (água) para as variáveis ângulo de contato e área molhada de gotas considerando as superfícies adaxiais e abaxiais de cada espécie, Para comparar as diferentes superfícies vegetais e artificiais foi utilizado delineamento inteiramente ao acaso com oito tratamentos representados pelas superfícies utilizando água, e as caldas com fungicidas sem adjuvantes separadamente. Os valores dos dados obtidos submetidos à análise de variância e as médias comparadas entre si pelo teste de Tukey (p<0,05). O uso de adjuvantes associados às caldas fungicidas promoveu reduções nos valores de tensão superficial com consequência no aumento de tamanho de gotas evitando, assim, maiores perdas por deriva, além de melhorar a uniformidade das gotas. Verificou-se que o uso dos adjuvantes em associação com os fungicidas contribuem com a redução do ângulo de contato das gotas melhorando o espalhamento sobre as diferentes superfícies, com destaque ao adjuvante siliconado. As folhas de soja se destacaram por apresentarem o menor espalhamento de gotas sobre sua superfície adaxial e abaxial seguida pelas superfícies de citros, parafilme, cana, café algodão, milho e vidro. A ocorrência de diferenças de espalhamento entre as superfícies adaxiais e abaxiais bem como a sua intensidade dependem da espécie vegetal e do produto utilizado. / The studies and researches in Application Technology are important to improve the application of spraying liquids in Brazil and in the world. Knowing the effect of spraying liquids containing different plant protection products and adjuvants in relation to different leaf surfaces is very important to position the best combinations of spraying liquids, in order to promote the desired effect of the droplet on the target. In this way, the present work had as objective to evaluate the spreading of spraying liquids containing two widely used fungicides in agriculture in association with adjuvants, besides water, on different vegetal and artificial surfaces. It were carried out experiments to analyse the surface tension, contact angle, droplet wet area and the droplet size produced by the XR 11002 tip of the different treatments. The analyzed surfaces were leaves of citrus, coffee, corn, soybean, cotton, cane, glass and parafilm. The design was entirely randomized in the 2 (fungicides) x 5 (adjuvants) + 1 (water) factorial scheme for the variables surface tension and droplet size and 2 (fungicides) x 2 (adaxial and abaxial surfaces) x 5 (adjuvants) + 1 (water) for the variables contact angle and wetted area of droplets considering the adaxial and abaxial surfaces of the leaves, In order to compare the different vegetal and artificial surfaces, a completely randomized design was used with eight treatments represented by the surfaces using water, and the fungicides without adjuvants separately. The values of the obtained data were submitted to the analysis of variance and the averages compared to each other by the Tukey's test (p <0.05). The use of adjuvants associated with the fungicidal spraying liquids promoted reductions in the values of surface tension with consequent increase in the droplet size, thus avoiding greater drift losses, besides improving the uniformity of the droplets. It has been found that the use of the adjuvants in association with the fungicides contributes to the reduction of the contact angle of the droplets improving the spreading, with emphasis on the siliconized adjuvant. The soybean leaves showed the smallest spreading of droplets on their adaxial and abaxial surface followed by the surfaces of citrus, parafilm, sugar cane, cotton, coffee, corn and glass. The occurrence of spreading differences between the adaxial and abaxial surfaces as well as their intensity depends on the plant species and the product used.

A citricultura é um setor de grande importância para o país na geração de divisas, formação de renda e capital. Um dos fatores críticos no sucesso de um sistema de irrigação localizada é a definição em projeto da fração de área molhada no solo. Face às dificuldades técnicas encontradas nesse tipo de estudo, até o presente, inexistem na literatura científica trabalhos confiáveis que estabeleçam os valores ótimos de fração de área molhada no solo para as diferentes culturas e condições edafoclimáticas. Esse trabalho teve como objetivo principal avaliar o efeito do molhamento parcial do solo para plantas jovens de laranja Valência sob porta-enxerto de citrumelo Swingle e limão Cravo em dois tipos de solo. Os objetivos secundários foram: a) Avaliar o método da sonda de dissipação térmica na estimativa da transpiração em laranja Valência e b) Estabelecer as relações entre a transpiração das plantas, sem restrição de área de solo, molhado e a demanda atmosférica. O experimento foi conduzido em estufa nas dependências do Departamento de Engenharia de Biossistemas da ESALQ/USP. Foi testado o molhamento de 12,5% da área do solo. Mudas de laranja foram plantadas em caixas de 500 L internamente divididas em compartimentos. Determinou-se simultaneamente a transpiração de todas as plantas através de sondas de dissipação térmica, o conteúdo de água no solo, o crescimento das plantas (área foliar e diâmetro de caule) e o número total de frutos por planta. Inicialmente todas as plantas tiveram 100% do volume de solo ocupado pelas raízes irrigado, sendo determinada a contribuição relativa de cada compartimento da caixa na transpiração. Completada a secagem dos compartimentos não irrigados, foi calculado o percentual da transpiração relativa a 100% de área molhada do solo pela relação entre transpiração de cada planta e a transpiração média das plantas com 100% da área do solo molhado. De acordo com os resultados, conclui-se que ocorre redução da transpiração pela restrição da área de solo molhado, sendo esta redução influenciada não só pelo tipo de solo e porta-enxerto, como também pelo número de dias após início da irrigação parcial, demanda evaporativa da atmosfera e fase fenológica da planta. A adaptação do sistema radicular à redução da área molhada ocorreu em torno de 156 dias. Apesar da redução da taxa transpiratória, não houve diferença significativa entre os tratamentos em relação ao crescimento vegetativo e número de frutos por planta. A transpiração das plantas foi influenciada pelo tipo de porta-enxerto utilizado, do crescimento em área foliar e da fase fenológica, sendo que sua relação com a evapotranspiração de referência não é linear em toda faixa de demanda evaporativa da atmosfera. O método da sonda de dissipação térmica, com calibragem específica e correção dos gradientes térmicos naturais no caule, mostrou-se eficaz na avaliação da transpiração de plantas jovens de laranjeira. / The citrus industry is a great important sector to the Brazilian country to generate foreign currency income and capital formation. The determination of the fractional wetted area in the soil is a critical factor in the success of an irrigation system project. Due to the technical difficulties to find out dates in this kind of study, there are no reliable studies in the scientific literature to establish the optimal values of fractional wetted area for different crops, soil and weather. This study aims to evaluate the effect of partial wetting of the soil for Valencia orange under the rootstock Swingle and Rangpur in two soil types. As secondary objectives: a) To evaluate the method of heat dissipation probe in the transpiration estimative in the Valencia orange plant, b) to establish the relationship between the atmospheric demand and plant transpiration, without restriction wetted area. The experiment was conducted in a greenhouse in the Biosystems Engineering Department of ESALQ/USP, Piracicaba-SP, Brazil. It was tested the wetness of 12.5% of the area of soil. For this, orange seedlings were planted in boxes of 500 L internally divided into compartments. It was simultaneously determined transpiration of all plants using heat dissipation probes (sap flow), measured the soil water content, plant growth (leaf area, stem diameter) and the total number of fruits per plant. Initially, it was irrigated 100% of root system of all plants and it was determined the contribution of each compartment of the box in the plant transpiration by the difference in water storage in the soil and measured plant transpiration. When it was completed the drying of not irrigated compartment, it was calculated the percentage of transpiration on 100% of the wetted soil area by the relationship between transpiration of each plant and the average of plant transpiration with 100% of the wetted area. According to the results can be conclude that occur reduction in the transpiration flow due to the restricting of wet soil area and this reduction is not only influenced by soil type and rootstock, but also due to the number of days after onset of partial irrigation, atmospheric evaporative demand and plant phenological stage. The adaptation of the root system to the reduction of the wet soil volume occurred around 156 days. Despite of the reduction in transpiration rate, it was not observed significant difference between treatments in relation to vegetative growth and fruit number per plant. Plant transpiration was influenced by the type of rootstock used, leaf area growth and phenological stage. However the relationship between the plant transpiration and EToPM is not linear across the range of atmospheric evaporative demand. The method of heat dissipation probe, calibrated specifically for the study and with correction of the thermal natural gradient in the trunk was effective in the evaluation of the seedlings of orange transpiration.

A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.

A need was identified for a set of basic design tools for Multi-Effect Distillation (MED) plant evaporators. This led to an investigation into the different types of evaporators as well as further research on horizontal falling film evaporators as used in the MED process. It also included the theory on these types of evaporators. In order not to duplicate existing design tools, an investigation was also performed on some of the tools that are currently available. The first set of tools that were developed were tools, programmed in EES (Engineering Equation Solver), for the vacuum system and the evaporator. These programs can be used to simulate different parameters (like different mass flows and temperatures). That enables the correct selection of components for the vacuum system and can be used to address sizing issues around the evaporator. It can also be used to plan the layout of the plant. The second of the design tools was developed by designing and building a flow pattern test section. From the flow pattern test section a set of curves for the wetted length under different conditions was obtained which can be used in order to design the sieve tray. This set of curves was found to be accurate for municipal as well as seawater and can be used in the design of the sieve tray of the evaporator. Further development can be done by implementing the figures of the wetted length into a simulation package like, for example, Flownex (a system CFD (Computational Fluid Dynamics) code that enables users to perform detail design, analysis and optimization of a wide range of thermal-fluid systems). The background gained from the study done on the evaporator can also be implemented into such a package. This could solve the problem of different design packages by creating a single design package with all of the above mentioned options included. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2009.