Experimental study on high-pressure droplet evaporation using microgravity conditions

Nomura, Hiroshi; Ujiie, Yasushige; Rath, H. J.; Sato, Junich; Kono, Michikata

doi:10.1016/s0082-0784(96)80344-4

Cited by 230 publications

(147 citation statements)

References 14 publications

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“…A comprehensive numerical model to study a vaporizing n-heptane droplet in a forced convective environment has been presented. The validation of their numerical results with the experimental results [13] is also reported. In the experiments [13], the droplet had been moved from the droplet-generator to a test portion for a short period of time, which imparted an initial small relative velocity between the droplet and the surrounding gas.…”

Section: Introductionmentioning

confidence: 79%

“…The validation of their numerical results with the experimental results [13] is also reported. In the experiments [13], the droplet had been moved from the droplet-generator to a test portion for a short period of time, which imparted an initial small relative velocity between the droplet and the surrounding gas. When such a small relative motion was included in the numerical model, their model was able to predict the experimental time histories quite accurately.…”

Section: Introductionmentioning

confidence: 79%

“…The unsteady equations of mass, species, momentum and energy conservation in axisymmetric spherical coordinates are solved using the finite-volume and SIMPLEC methods. The axisymmetric numerical model has been thoroughly validated against the extensive microgravity experimental data of Nomura et al [13]. The details of the governing equations, solution method, evaluation of variable thermo-physical properties, convergence criteria, boundary and initial conditions, and validation are available elsewhere [28,29].…”

Section: Numerical Modelmentioning

confidence: 99%

“…Several investigators [4][5][6][7][8][9][10][11][12], have addressed the problem of gas solubility in their research works on high pressure droplet vaporization. Nomura et al [13] have measured experimentally the temporal variation of (d / d 0 ) 2 for an n-heptane droplet at different ambient pressures and temperatures under microgravity conditions. Several investigators have reported about the transition from subcritical to supercritical vaporization regime and several others have studied the characteristics of droplet gasification at supercritical conditions [14][15][16][17][18][19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

“…A numerical model which has been developed and thoroughly validated [28,29]against the experimental results available in the literature [13], has been employed for the simulations. Vaporization of an n-heptane droplet with an initial diameter of 100 μm and at an initial temperature of 300 K, within a zero-gravity, N 2 environment at 1000 K has been studied for a wide range of ambient pressures (0.1 -9 MPa) and initial freestream velocities (0.25 -5 m/s).…”

Section: Introductionmentioning

confidence: 99%

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Subcritical and supercritical droplet evaporation within a zero-gravity environment: Low Weber number relative motion

Zhang

Raghavan

Gogos

2008

International Communications in Heat and Mass Transfer

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A validated comprehensive axisymmetric numerical model, which includes the high pressure transient effects, variable thermo-physical properties and inert species solubility in the liquid phase, has been employed to study the evaporation of moving n-heptane droplets within a zero-gravity nitrogen environment, for a wide range of ambient pressures and initial freestream velocities. At the high ambient temperature considered (1000 K), the evaporation constant increases with the ambient pressure. At low ambient pressure, the evaporation constant becomes almost a constant during the end of the lifetime. At high ambient pressures, the transient behavior is present throughout the droplet lifetime. The final penetration distance of a moving droplet decreases exponentially with increasing ambient pressure. The average evaporation constant increases with ambient pressure. The variation is almost linear for reduced ambient pressures smaller than approximately 2. For higher values, depending on the initial freestream velocity, the average evaporation constant either becomes a constant (at low initial freestream velocities) or it non-linearly increases (at high initial freestream velocities) with the ambient pressure. Droplet lifetime decreases with increasing ambient pressure and/or increasing initial freestream velocity.

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Section: Introductionmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 79%

Section: Numerical Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Subcritical and supercritical droplet evaporation within a zero-gravity environment: Low Weber number relative motion

Zhang

Raghavan

Gogos

2008

International Communications in Heat and Mass Transfer

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Detailed modeling of the evaporation and thermal decomposition of urea‐water solution in SCR systems

2011

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This work aims to develop a multi-component evaporation model for droplets of urea-watersolution (UWS) and a thermal decomposition model of urea for automotive exhausts using the Selective Catalytic Reduction (SCR) systems. In the multi-component evaporation model, the influence of urea on the UWS evaporation is taken into account using a NRTL activity model. The thermal decomposition model is based on a semi-detailed kinetic scheme accounting not only for the production of ammonia (NH 3 ) and isocyanic acid (HNCO), but also for the formation of heavier solid by-products (biuret, cyanuric acid and ammelide). This kinetics model has been validated against gaseous data as well as solid-phase concentration profiles obtained by Lundstroem et al. (2009) andSchaber et al. (2004). Both models have been implemented in IFP-C3D industrial software in order to simulate UWS droplet evaporation and decomposition as well as the formation of solid by-products. It has been shown that the presence of the urea solute has a small influence on the water evaporation rate, but its effect on the UWS temperature is significant. In addition, the contributions of hydrolysis and thermolysis to urea decomposition have been assessed. Finally, the impacts of the heating rate as well as gas-phase chemistry on urea decomposition pathways have been studied in detail. It has been shown that reducing the heating rate of the UWS causes the extent of the polymerization to decrease because of the higher activation energy.

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Assessment of Conventional Droplet Evaporation Models for Spray Flames

Zoby

Kronenburg

Navarro‐Martinez

et al. 2012

High Performance Computing in Science and Engineering '11

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Experimental study on high-pressure droplet evaporation using microgravity conditions

Cited by 230 publications

References 14 publications

Subcritical and supercritical droplet evaporation within a zero-gravity environment: Low Weber number relative motion

Subcritical and supercritical droplet evaporation within a zero-gravity environment: Low Weber number relative motion

Detailed modeling of the evaporation and thermal decomposition of urea‐water solution in SCR systems

Assessment of Conventional Droplet Evaporation Models for Spray Flames

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