Μm Diameter Particles Research Articles

Study on the mixing and migration behavior of micron-size particles in acoustofluidics

Slow mass transfer remains a limiting factor in microfluidic devices, as it is purely based on molecular diffusion. Hence, the completion of a targeted chemical reaction is extremely slow. Acoustic streaming is a great methodology to create lateral convection in otherwise laminar flow operated channels and offers the possibility to reduce mass transfer resistance dramatically. Moreover, the acoustic field can elegantly by used to handle micron-sized particles. Large particles (>2 µm), experience a radiation force that is much larger than the drag force related to streaming and will rapidly focus at either the node or anti-node of the standing pressure wave in the channel. In the present contribution, the mass transfer rate in both a drag force dominated as well as in a radiation force dominated regime is studied by in situ tracking polystyrene particles of respectively 0.5 and 5 µm. The 5 µm particles focus on the pressure node experiencing a migration velocity that decreases as the node position is approached, whereas the 0.5 µm particles remain in the vortex flow, characteristic for acoustic streaming. The experimentally obtained migration rates are in accordance with numerical simulations, suggesting that operational parameters as actuator displacement have been chosen appropriately. Mixing times of parallel flows were assessed and revealed an order of magnitude enhancement for small molecules, up to four order of magnitudes for 0.5 µm diameter particles.

Model of the solar-driven reduction of cobalt oxide in a particle suspension reactor

We develop a model to investigate the impact of volume fraction and extent of mixing on the thermal efficiency with which a cavity-based particle suspension solar reactor reduces Co3O4 into CoO and O2. Thermal efficiency is defined as the fraction of solar energy used to drive the endothermic reduction. In the model, particles move continuously through the reactor in either mixed or plug flow—mixing conditions that give rise to isothermal and nonisothermal suspensions, respectively—and reduce at a rate governed by shrinking core kinetics, the parameters of which are determined using thermogravimetric data. Radiation is simulated using the Monte Carlo Ray Tracing technique. The model is applied to a reactor heated by 4 kW of point-focused solar radiation with a mean concentration ratio of 1400 suns containing monodisperse suspensions of 40 μm diameter particles with volume fractions between 1×10−5 and 1×10−2. Thermal efficiency is insensitive to mixing for the two conditions considered. The maximum thermal efficiency obtained for mixed flow with an isothermal suspension is 34.1% at 102 g min−1 and a volume fraction of 2×10−4. At the same volume fraction, the maximum thermal efficiency for nonisothermal plug flow is 33.2% at 94 g min−1. Thermal efficiency is more sensitive to the volume fraction, but only below a threshold value of 2×10−4. Thus, from the perspective of coupling heat transfer to the chemical reaction, design and operational efforts of particle suspension reactors for the reduction of cobalt oxide should focus on generating suspensions of at least this threshold value rather than on mixing the particles within the suspension.

Study of heat transfer with surface treatment in pre-coolers for aeroengine applications

The effect of surface roughness on convective heat transfer and pressure drop is assessed for a simplified pre-cooler system for application in high-speed airbreathing engines. The pre-cooler system comprises of four circular cylinders in cross-flow inside a square duct. The cylindrical wires of 1 mm diameter were textured using an economical method of surface treatment, via sand-blasting with 100 µm (diameter) particles. Experiments were conducted at Reynolds numbers ranging from 600 to 8000. The Nusselt number was observed to decrease for the rough wires, indicating decreased convective heat transfer rates. Moreover, roughness was found to have no appreciable effect on pressure drop for these conditions. This is attributed to a fully developed turbulent duct flow upstream of the wires, which was confirmed by observing the Nusselt-Reynolds number correlation for treated and untreated cases. Surface roughness strategy in pre-coolers for an ascent trajectory of a high-speed airbreathing engine is also discussed.

Narrow bore post column derivatisation assays via reaction flow chromatography

This study highlights the capability to conduct a post column derivatisation (PCD) process with a narrow bore, low volume column. A reaction flow (RF) HPLC column (30 mm × 2.1 mm internal diameter (i.d.), 3 μm particle diameter) enabled the selective detection of phenols for both a simple standard mixture and a complex sample represented by green tea. The resolving power and sensitivity obtained were similar to an analytical scale (4.6 mm i.d.) RF HPLC column of the same format. However, the baseline noise experienced was higher when the assay was scaled down from the RF 4.6 mm i.d. to the RF 2.1 mm i.d. narrow bore column. The PCD mixing and reaction speed inside the RF column outlet (frit and head-fitting design) enabled the coupling of PCD protocols with “UHPLC-type” low volume columns and systems without significant loss in separation performance. In comparison to a conventional analytical scale PCD approach the scaled down narrow bore RF approach demonstrated 40 times greater sensitivity in terms of S/N. Scaled down PCD is vital for decreased consumption and cost without significant loss in separation performance.

The effect of the frictional heat on retention and efficiency in thermostated or insulated chromatographic columns packed with sub-2-μm particles

The mass-transfer properties of a core-shell packing material with 1.6 μm particle diameter, and that of a fully porous packing material with 1.7 μm particle diameter were investigated and compared. The first absolute and the second central moments of the peaks of the homologous series of alkylbenzenes, over a wide range of mobile phase velocities were measured and used for the calculation of the mass-transfer coefficients. For the evaluation of the band broadening caused by the thermal dissimilarities, the measurements were carried out under thermostated conditions and also at near adiabatic insulation of the columns.

Human Cell Encapsulation in Gel Microbeads with Cosynthesized Concentric Nanoporous Solid Shells

AbstractEncapsulation of therapeutic cells in core–shell microparticles has great promise for the treatment of a range of health conditions. Unresolved challenges related to control of the particle morphology, mechanical stability, and immunogenicity hinder dissemination of this promising approach. Here, a novel polymer material for cell encapsulation and a combined novel, easy to control, synthesis method are introduced. Core–shell cell encapsulation is demonstrated with a concentric core–shell morphology formed during a single UV exposure, resulting in particles that consist of a synthetic hydrogel core of polyethylene glycol diacrylate and a solid, but porous, shell of off‐stoichiometric thiol‐ene. The encapsulated human cells in 100 µm diameter particles have >90% viability. The average shell thickness is controlled between 7 and 13 µm by varying the UV exposure, and the shell is measured to be permeable to low molecular weight species (<180 Da) but impermeable to higher molecular weight species (>480 Da). The unique material properties and the orthogonal control of the microparticle core size, shell thickness, shell permeability, and shell surface properties address the key unresolved challenges in the field, and are expected to enable faster translation of novel cell therapy concepts from research to clinical practice.

Numerical investigation of water droplets trajectories during natural gas dehydration inside supersonic separator

Reliable estimation of the condensed water droplets trajectories inside Supersonic separators (3Ss) during the dehydration process is essential for proper design and safe operation. Most of previous researches ignored the actual sizes of condensed droplets and predicted the particles trajectories for pre-specified diameters. In this article and for the first time, real trajectories are computed by considering the actual particle size distribution (PSD) of the condensed droplets in the presence of swirl, nucleation and growth processes during the dehydration of methane rich natural gas (MRNG) inside Laval nozzle for various diffuser angles. Furthermore, the injection of water droplets to facilitate the condensation process has not been addressed previously.Our simulation results indicate that even for the most optimal geometry and at extremely large centrifugal accelerations of 500,000 g, the condensed particles from MRNG are exceedingly small and can't reach the 3S walls for practical straight tube lengths. Our findings are verified with several previously reported experimental measurements and theoretical investigations results, borrowed from literature. To ensure proper dehumidification, sufficiently large water droplets are assumed to be injected preferably after the throat location. The computed results indicate that by injecting 5 μm diameter particles into MRNG of Khangiran refinery sweet gas stream and increasing its wetness fraction up to 0.12, the dehydration process is successfully achieved in an optimally designed supersonic separator.

Secondary sulfate is internally mixed with sea spray aerosol and organic aerosol in the winter Arctic

Abstract. Few measurements of aerosol chemical composition have been made during the winter–spring transition (following polar sunrise) to constrain Arctic aerosol–cloud–climate feedbacks. Herein, we report the first measurements of individual particle chemical composition near Utqiaġvik (Barrow), Alaska, in winter (seven sample days in January and February 2014). Individual particles were analyzed by computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX, 24 847 particles), Raman microspectroscopy (300 particles), and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS, 290 particles). Sea spray aerosol (SSA) was observed in all samples, with fresh and aged SSA comprising 99 %, by number, of 2.5–7.5 µm diameter particles, 65–95 % from 0.5–2.5 µm, and 50–60 % from 0.1–0.5 µm, indicating SSA is the dominant contributor to accumulation and coarse-mode aerosol during the winter. The aged SSA particles were characterized by reduced chlorine content with 94 %, by number, internally mixed with secondary sulfate (39 %, by number, internally mixed with both nitrate and sulfate), indicative of multiphase aging reactions during transport. There was a large number fraction (40 % of 1.0–4.0 µm diameter particles) of aged SSA during periods when particles were transported from near Prudhoe Bay, consistent with pollutant emissions from the oil fields participating in atmospheric processing of aerosol particles. Organic carbon and sulfate particles were observed in all samples and comprised 40–50 %, by number, of 0.1–0.4 µm diameter particles, indicative of Arctic haze influence. Soot was internally mixed with organic and sulfate components. All sulfate was mixed with organic carbon or SSA particles. Therefore, aerosol sources in the Alaskan Arctic and resulting aerosol chemical mixing states need to be considered when predicting aerosol climate effects, particularly cloud formation, in the winter Arctic.

Untargeted profiling of Glycyrrhiza glabra extract with comprehensive two-dimensional liquid chromatography-mass spectrometry using multi-segmented shift gradients in the second dimension: Expanding the metabolic coverage.

Metabolic profiling of Glycyrrhiza glabra using comprehensive two-dimensional liquid chromatography (LC×LC) coupled with photodiode array (PDA) and mass spectrometry (MS) detection is described. The separation was conducted under reversed-phase conditions, using a combination of first dimension (1 D) 150mm microbore cyano column utilising 2.7 μm diameter (dp ) particles, and second dimension (2 D) 50mm superficially porous octadecylsilica column with 2.7μm dp particles. A multi-segmented shift gradient (MSG) for the 2 D separation was developed, and the orthogonality achieved was compared with other modes of gradients, such as full in-fraction, and shift gradient systems. Results demonstrated a significant expansion of metabolic coverage using MSG in 2 D, providing the highest measure of orthogonality compared to other gradient modes. Compound identifications were performed by employing complementary data from PDA and MS detection, with reference to structural group-type distribution in 2D space. A total of ca. 120 compounds were detected, and among them 37 were tentatively identified, distributed over the chemical families of glycosylated flavanones, triterpene saponins, and others. In comparison with one-dimensional LC, the total number of compounds detected was ca. 2-fold greater when LC×LC was employed. To the best of our knowledge, this is the first demonstration of the MSG mode in LC×LC, representing a powerful strategy to expand the metabolic coverage for analysis of plant-derived extracts, containing a multitude of different phytochemical classes.

Microplastics in Swiss Floodplain Soils.

Microplastics (MPs) are small (<5 mm diameter) but have clear implications for the environment. These artificial particles are found in and pose threats to aquatic systems worldwide. MPs have terrestrial sources, but their concentrations and fates in the terrestrial environment are poorly understood. While global plastic production continues to increase, so do the environmental concentrations and impacts of MPs. In this first study of MPs in floodplain soils, we developed a method for identifying, quantifying, and measuring the sizes of most commonly produced MPs in soil by FT-IR microscopy. For small MP (<1 mm) analysis, MP were separated by density separation and oxidation of organic matter. In this study we analyzed 29 floodplains in Swiss nature reserves associated with catchments covering 53% of Switzerland. We found evidence that 90% of Swiss floodplain soils contain MPs. The highest MP concentrations were associated with the concentration of mesoplastics (5 mm - 2.5 cm diameter), indicating plastic waste as source. Furthermore, MP concentration was correlated with the population of the catchment. The wide distribution of MPs, their presence in remote unsettled high mountain areas, decoupling of MEP and MP compositions, and the dominance of MPs by small (<500 μm diameter) particles, indicate that MPs enter soils via diffuse aeolian transport.

Visibility in airborne volcanic ash: considerations for surface transportation using a laboratory-based method

All modes of surface transportation can be disrupted by visibility degradation caused by airborne volcanic ash. Despite much qualitative evidence of low visibility on roads following historical eruptions worldwide, there have been few detailed studies that have attempted to quantify relationships between visibility conditions and observed impacts on network functionality and safety. In the absence of detailed field observations, such gaps in knowledge can be filled by developing empirical datasets through laboratory investigations. Here, we use historical eruption data to estimate a plausible range of ash-settling rates and ash particle characteristics for Auckland city, New Zealand. We propose and implement a new experimental set-up in controlled laboratory conditions, which incorporates a dual-pass transmissometer and solid aerosol generator, to reproduce these ash-settling rates and calculate visual ranges through the associated airborne volcanic ash. Our findings demonstrate that visibility is most impaired for high ash-settling rates (i.e. > 500 g m−2 h−1) and particle size is deemed the most influential ash characteristic for visual range. For the samples tested (all < 320 μm particle diameter), visibility was restricted to ~ 1–2 m when ash settling was replicated for very high rates (i.e. ~ 4000 g m−2 h−1) and was especially low when ash particles were fine-grained, more irregular in shape and lighter in colour. Finally, we consider potential implications for disruption to surface transportation in Auckland through comparisons with existing research which investigates the consequences of visual range reduction for other atmospheric hazards such as fog. This includes discussing how our approach might be utilised in emergency and transport management planning. Finally, we summarise strategies available for the mitigation of visibility degradation in environments contaminated with volcanic ash.

Regional flow and deposition variability in adult female lungs: A numerical simulation pilot study

BackgroundDespite the promise of respiratory simulations improving diagnosis and treatment of pulmonary diseases, model predictions have yet to be translated into the clinical setting. Current state-of-the-art in silico models have not yet incorporated subject variability in their predictions of airflow distributions and extent of deposited particles. Until inter-subject variability is accounted for in lung modeling, it will remain impossible to translate model predictions into clinical practice. MethodsAirflow and particle trajectories (dp=1,3,5μm) are calculated in three subject-specific female adults by performing physiologically-based simulations. The computation framework features the ability to track air and particles throughout the respiration cycle and in the entire lung. Airway resistances, air velocities, and local deposition sites are correlated to airway anatomical features. FindingsSmaller airway diameters are correlated to larger airway resistances and pressure gradients in one subject compared to the other two. Irregular shape of the airway and flow direction (e.g. inspiration or expiration) correspond with peak velocities and secondary flow motions. Largest subject variability in deposition between conducting and respiratory zones is seen for 1 μm diameter particles. Little difference in total deposition is found among subjects. Localized deposited particle concentration hotspots are linked to airway anatomy and flow motion. InterpretationSimulation predictions provide a first look into the correlation of anatomical features with airflow characteristics and deposited particle concentrations. Global deposition percentages ranged (at most, by 20%) between subjects and variances in localized deposition hotspots are correlated to variances in flow characteristics.

Hydrometallurgical Processing of a Nigerian Galena Ore in Nitric Acid: Characterization and Dissolution Kinetics

The physico-chemical characterization and dissolution kinetics study of a Nigerian galena ore in nitric acid has been undertaken. The effects of acid concentration, temperature, particle size, stirring speed and solid/liquid ratio on the leaching of galena were investigated. The X-ray fluorescence data showed that the galena ore used in the study exists mainly as PbS. Lead (Pb) was detected as the major metal for galena with metals such as Na, Ca, Fe, Zn, Al and Mg occurring as minor elements. The XRD analysis also confirmed the originality of the galena ore as it revealed that galena exists mainly as lead sulphide (PbS). The Fourier transform infrared (FTIR) analysis also supported the XRF and XRD analysis by revealing the presence of sulphur in the ore. The scanning electron micrograph (SEM) analysis revealed a high level of crystallinity of the ore. Results of the leaching studies showed that galena dissolution in nitric acid (HNO3) increases with increasing concentration of nitric acid, temperature and stirring rate, and decreases with increasing particle diameter and solid/liquid ratio. In 10 M HNO3 at a temperature of 90°C using 75 μm particle diameter with solid/liquid ratio of 20 g/L and stirring speed of 540 rpm, about 84.5% of galena was dissolved in 150 minutes. The values of activation energy, order of reaction and Arrhenius constant calculated at the conditions above for galena were 27.01 KJ/mol, 0.93, 26.71 s-1 respectively. The mechanism of dissolution of galena was established to follow the shrinking core model for the diffusion controlled mechanism, with surface chemical reaction as the rate controlling step for the leaching process. Finally, the XRD analysis of the post-leaching residue revealed the presence of gahnite and anglesite.

Order-disorder morphologies in rapidly solidified ε/ε′-Ni5Ge3 intermetallic

Congruently melting, single-phase Ni5Ge3 (Tm = 1185 °C) has been rapidly solidified via drop-tube processing wherein powders, with diameters between 850 - 53 μm, are produced. At low cooling rates (850–150 μm diameter particles, 700–7800 K s−1) the dominant solidification morphology, revealed after etching, is that of isolated plate & lath microstructure in an otherwise featureless matrix. At higher cooling rates (150–53 μm diameter particles, 7800–42000 K s−1) the dominant solidification morphology is that of isolated faceted hexagonal crystallites, again imbedded within a featureless matrix. Selected area diffraction analysis in the TEM reveals the plate & lath, and isolated hexagonal crystallites, are a disordered variant of ε-Ni5Ge3, whilst the featureless matrix is the ordered variant of the same compound. Thermal analysis and in situ heating in the TEM indicate a reversible solid-state order-disorder transformation between 470 - 485 °C.

A Pumpless Acoustofluidic Platform for Size-Selective Concentration and Separation of Microparticles.

We have designed a pumpless acoustofluidic device for the concentration and separation of different sized particles inside a single-layered straight polydimethylsiloxane (PDMS) microfluidic channel. The proposed device comprises two parallel interdigitated transducers (IDTs) positioned underneath the PDMS microchannel. The IDTs produce high-frequency surface acoustic waves that generate semipermeable virtual acoustic radiation force field walls that selectively trap and concentrate larger particles at different locations inside the microchannel and allow the smaller particles to pass through the acoustic filter. The performance of the acoustofluidic device was first characterized by injecting into the microchannel a uniform flow of suspended 9.9 μm diameter particles with various initial concentrations (as low as 10 particles/mL) using a syringe pump. The particles were trapped with ∼100% efficiency by a single IDT actuated at 73 MHz. The acoustofluidic platform was used to demonstrate the pumpless separation of 12.0, 4.8, and 2.1 μm microparticles by trapping the 12 and 4.8 μm particles using the two IDTs actuated at 73 and 140 MHz, respectively. However, most of the 2.1 μm particles flowed over the IDTs unaffected. The acoustofluidic device was capable of rapidly processing a large volume of sample fluid pumped through the microchannel using an external syringe pump. A small volume of the sample fluid was processed through the device using a capillary flow and a hydrodynamic pressure difference that did not require an external pumping device.

Direct Measurement of Interparticle Forces of Titan Aerosol Analogs (“Tholin”) Using Atomic Force Microscopy

AbstractTo understand the origin of the dunes on Titan, it is important to investigate the material properties of Titan's organic sand particles on Titan. The organic sand may behave distinctively compared to the quartz/basaltic sand on terrestrial planets (Earth, Venus, and Mars) due to differences in interparticle forces. We measured the surface energy (through contact angle measurements) and elastic modulus (through Atomic Force Microscopy) of the Titan aerosol analog (tholin). We find that the surface energy of a tholin thin film is about 70.9 mN/m, and its elastic modulus is about 3.0 GPa (similar to hard polymers like PMMA and polystyrene). For two 20 μm diameter particles, the theoretical cohesion force is therefore 3.3 μN. We directly measured interparticle forces for relevant materials: tholin particles are 0.8 ± 0.6 μN, while the interparticle cohesion between walnut shell particles (a typical model materials for the Titan Wind Tunnel, TWT) is only 0.4 ± 0.1 μN. The interparticle cohesion forces are much larger for tholins and presumably Titan sand particles than materials used in the TWT. This suggests that we should increase the interparticle force in both analog experiments (TWT) and threshold models to correctly translate the results to real Titan conditions. The strong cohesion of tholins may also inform us how the small aerosol particles (∼1 μm) in Titan's atmosphere are transformed into large sand particles (∼200 μm). It may also support the cohesive sand formation mechanism suggested by Rubin and Hesp (2009), where only unidirectional wind is needed to form linear dunes on Titan.

Exposure to SVOCs from Inhaled Particles: Impact of Desorption.

Inhaled semivolatile organic compounds (SVOCs) are simultaneously present in gas and particle phases. Particles desorb a fraction of their SVOCs moving through the human respiratory tract (RT). Quantifying such desorption is challenging but important since gas- and particle-phase SVOCs deposit in different locations in the RT, encountering different cell populations with varying health consequences. This paper presents a mass transfer model to quantify this desorption process in the head, tracheobronchial, and alveolar regions of the RT. The desorption of SVOCs from inhaled particles can be gauged using the ratio of particle residence time to the time required to achieve particle/gas equilibrium. Results indicate that the larger this ratio is, the more likely particles desorb the SVOCs they carry. For particles smaller than 0.5 μm diameter and SVOCs with a particle/gas partition coefficient (unitless) of 1010, accounting for desorption reduces the estimated particle-phase SVOC concentrations in the alveolar region by more than 35%; the reduction is almost 700% for 0.05 μm diameter particles. In hypothetical scenarios representing common indoor and outdoor situations, neglecting desorption significantly overestimates the concentration of ultrafine particle associated SVOCs in the alveolar region. This model is a preliminary step toward more nuanced estimates of exposure to inhaled SVOCs.

Morphology of Spherulites in Rapidly Solidified Ni3Ge Droplets

The congruently melting, single phase, L12 intermetallic β-Ni3Ge has been subject to rapid solidification via drop-tube processing. Four different cooling rates are used in this process, at very low cooling rates (≥850 μm diameter particles, ≥700 K s−1) and slightly higher cooling rates (850–500 μm diameter particles, 700–1386 K s−1) the dominant solidification morphology, revealed after etching, is that of isolated spherulites in an otherwise featureless matrix. At higher cooling rates, (500–300 μm diameter particles, 1386–2790 K s−1 and (300–212 μm diameter particles, 2790–4600 K s−1) mixed spherulite and dendritic morphologies are observed. Indeed, at the higher cooling rate dendrites with side-branches composed of numerous small spherulites are observed. Selected area diffraction analysis in the TEM indicate that the formation of spherulites is due to an order-disorder transformation. Dark-field TEM imaging has confirmed that the spherulites appear to consist of lamellae of the ordered phase, with disordered material in the space between the lamellae. The lamellar width within a given spherulite is constant, but the width is a function of cooling rate, with higher cooling rates giving finer lamellae. As such, there are many parallels with spherulite growth in polymers.

Interface Observation of Aluminum-Coated Carbon Nanofibers Prepared by in Situ Chemical Vapor Deposition

The compatibility of carbon nanofibers (CNFs) with aluminum is important for the fabrication of CNF-reinforced aluminum matrix composites with superior mechanical and thermal properties. In this study, aluminum was deposited on CNFs by in situ chemical vapor deposition (CVD) utilizing I2 for the transportation of aluminum atoms. The microstructure of the aluminum-coated CNFs and the crystal structure of the aluminum coating layers were studied. When aluminum powder with ∼3 μm diameter particles, CNFs, and I2 powder were mixed in the molar ratio 1:1:0.1 and annealed at 500 °C for 48 h, the coating layer formed was polycrystalline and exhibited preferential orientation of the (002) and (111) aluminum planes; the grain size of aluminum in the coated layer was ∼5 nm, the interface structure was governed by the CNF surface structure, and an amorphous region or aluminum oxycarbide (Al4O4C or Al2OC) was formed at the interface. When larger 106–180 μm particles of aluminum were used, a larger amount of I2 was req...

Improved combustion model of boron particles for ducted rocket combustion chambers

A combustion model of boron particles for detailed Computational Fluid Dynamics (CFD) based simulations of ducted rocket combustion chambers is studied. It is aimed to construct a model for combustion of boron containing gas mixtures ejected from a solid propellant gas generator. This model includes all main physical processes required to define an accurate particle combustion simulation. The reaction rate modeling in similar, previous studies are improved for ramjet combustion chambers and this model provides better predictions for all particle sizes. The reactions in the ignition stage are reformulated as competing reactions for consumption of (BO)n polymers. Large discrepancies between the experimental and calculated ignition times for the 3 μm diameter particles in similar studies are eliminated. The developed model is added to a commercial CFD solver and can be used along with gas phase detailed turbulent combustion simulations of ducted rocket combustion chambers. Our simulation approach has provided us an effective tool, which allows us to forecast the effects of the changes on the performance and efficiency. This detailed combustion model is validated with existing experimental results available in open literature. The model is also compared with the results of similar previous studies.