Christopher C. Jelloian, Nicolas Q. Minesi, R. Mitchell Spearrin, Augustin Tibère-Inglesse, Megan E. MacDonald, Brett A. Cruden
A mid-infrared laser absorption diagnostic was deployed to examine the evolution of thermophysical properties across a simulated Mars2020 shock layer in the Electric Arc Shock Tube (EAST) facility at NASA Ames. Rapid laser tuning techniques using bias-tee circuitry enabled quantitative temperature and number density measurements of [Formula: see text] and CO with microsecond resolution over a shock velocity range of 1.30–3.75 km/s. Two interband cascade lasers were utilized at 4.17 and 4.19 μm to resolve rovibrational [Formula: see text] lines spanning across [Formula: see text] to [Formula: see text] in the asymmetric stretch fundamental bands. In test cases with enough energy to dissociate [Formula: see text], a quantum cascade laser scanned multiple transitions of the CO fundamental bands near [Formula: see text]. The results are compared to the Data Parallel Line Relaxation (DPLR) code and Lagrange shock tube analysis (LASTA) simulations of the shock layer. A numerical simulation of the compressible boundary layer is used to account for measurement sensitivities to this flow feature in the EAST facility. Temperature and species transients are compared to multiple chemical kinetic models. The laser absorption data presented in this work can be used to refine the models used to simulate the aerothermal environment encountered during Mars entry.
{"title":"Mars2020 Entry Shock Layer Thermochemical Kinetics Examined by Megahertz-Rate Laser Absorption Spectroscopy","authors":"Christopher C. Jelloian, Nicolas Q. Minesi, R. Mitchell Spearrin, Augustin Tibère-Inglesse, Megan E. MacDonald, Brett A. Cruden","doi":"10.2514/1.t6868","DOIUrl":"https://doi.org/10.2514/1.t6868","url":null,"abstract":"A mid-infrared laser absorption diagnostic was deployed to examine the evolution of thermophysical properties across a simulated Mars2020 shock layer in the Electric Arc Shock Tube (EAST) facility at NASA Ames. Rapid laser tuning techniques using bias-tee circuitry enabled quantitative temperature and number density measurements of [Formula: see text] and CO with microsecond resolution over a shock velocity range of 1.30–3.75 km/s. Two interband cascade lasers were utilized at 4.17 and 4.19 μm to resolve rovibrational [Formula: see text] lines spanning across [Formula: see text] to [Formula: see text] in the asymmetric stretch fundamental bands. In test cases with enough energy to dissociate [Formula: see text], a quantum cascade laser scanned multiple transitions of the CO fundamental bands near [Formula: see text]. The results are compared to the Data Parallel Line Relaxation (DPLR) code and Lagrange shock tube analysis (LASTA) simulations of the shock layer. A numerical simulation of the compressible boundary layer is used to account for measurement sensitivities to this flow feature in the EAST facility. Temperature and species transients are compared to multiple chemical kinetic models. The laser absorption data presented in this work can be used to refine the models used to simulate the aerothermal environment encountered during Mars entry.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135540326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Generic plate and experiment-related high-fidelity models to study uncertainty propagation and transient processes for heat rejection problems are developed. The stochastic Biot numbers on the top and bottom surfaces of the plate, [Formula: see text] and [Formula: see text], and stochastic dimensionless input parameters, describing initial and convection boundary conditions, are introduced to define temperature variation in the modeled systems. The resulting uncertainty amplitude demonstrates a varying time evolution across a wide range of mean values of the input parameters. Depending on which input parameters are stochastic, the uncertainty may increase or decrease over time, or remain small for a given time interval in the case of the plate model. For small [Formula: see text], dimensionless characteristic time for a temperature variation curve to approach its steady state is [Formula: see text] and large. An extremum in a temperature variation curve may appear when the Biot numbers are unequal and disappears if [Formula: see text]. Results are nonsymmetric with respect to interchanging [Formula: see text] and [Formula: see text]. Despite the difference in shape, the temperature variation profile over a specific region in the experimental test section numerically described by the high-fidelity model is close to the corresponding results provided by the plate model for the same Biot numbers, convection boundary, and initial conditions.
{"title":"Modeling of Uncertainty Propagation for Transient Heat Rejection Problems","authors":"George Y. Panasyuk, Kirk L. Yerkes","doi":"10.2514/1.t6820","DOIUrl":"https://doi.org/10.2514/1.t6820","url":null,"abstract":"Generic plate and experiment-related high-fidelity models to study uncertainty propagation and transient processes for heat rejection problems are developed. The stochastic Biot numbers on the top and bottom surfaces of the plate, [Formula: see text] and [Formula: see text], and stochastic dimensionless input parameters, describing initial and convection boundary conditions, are introduced to define temperature variation in the modeled systems. The resulting uncertainty amplitude demonstrates a varying time evolution across a wide range of mean values of the input parameters. Depending on which input parameters are stochastic, the uncertainty may increase or decrease over time, or remain small for a given time interval in the case of the plate model. For small [Formula: see text], dimensionless characteristic time for a temperature variation curve to approach its steady state is [Formula: see text] and large. An extremum in a temperature variation curve may appear when the Biot numbers are unequal and disappears if [Formula: see text]. Results are nonsymmetric with respect to interchanging [Formula: see text] and [Formula: see text]. Despite the difference in shape, the temperature variation profile over a specific region in the experimental test section numerically described by the high-fidelity model is close to the corresponding results provided by the plate model for the same Biot numbers, convection boundary, and initial conditions.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For radiative transfer through an absorbing, scattering medium with planar geometry, the validity of the one-dimensional assumption is examined. Using the generalized zonal with Monte Carlo method as a solver, exact numerical solutions are generated to identify conditions under which the one-dimensional assumption is valid. Specifically, for the predictions of transmissivity and reflectivity for a collimated or diffuse energy beam through a planar slab, numerical data are presented to show that a medium aspect ratio (ratio of the width to the thickness) of five or more is a necessary but not sufficient condition for the data to agree with the one-dimensional result. The implication of this condition on the utilization of the one-dimensional radiative transfer assumption in some practical engineering problems such as pipe flow and thermal insulation is discussed.
{"title":"Validity of One-Dimensional Radiative Transfer in Participating Media","authors":"Walter W. Yuen","doi":"10.2514/1.t6850","DOIUrl":"https://doi.org/10.2514/1.t6850","url":null,"abstract":"For radiative transfer through an absorbing, scattering medium with planar geometry, the validity of the one-dimensional assumption is examined. Using the generalized zonal with Monte Carlo method as a solver, exact numerical solutions are generated to identify conditions under which the one-dimensional assumption is valid. Specifically, for the predictions of transmissivity and reflectivity for a collimated or diffuse energy beam through a planar slab, numerical data are presented to show that a medium aspect ratio (ratio of the width to the thickness) of five or more is a necessary but not sufficient condition for the data to agree with the one-dimensional result. The implication of this condition on the utilization of the one-dimensional radiative transfer assumption in some practical engineering problems such as pipe flow and thermal insulation is discussed.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135350966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qie Xiwang, Ji Jiadong, Li Feiyang, Deng Xu, Zhou Jianxin
A heat exchanger with a curved baffle for an elastic-tube bundle (ETB) is designed to effectively improve the performance based on a common ETB heat exchanger, and this paper systematically studies its vibration and heat transfer characteristics under different inlet velocity and structural parameters. The results indicate that the ETB vibration characteristics increase significantly with an increasing velocity, and the average amplitude of the ETB at [Formula: see text] is 4.51 times higher than that at [Formula: see text]. Similarly, the heat transfer performance subsequently decreases, but the average heat transfer coefficient of the ETB is significantly increased with the increase of the inlet velocity. When the long axis increases from 45 to 75 mm, the vibration intensity of the ETB decreases sharply, and the [Formula: see text] direction and the total vibration [Formula: see text] decrease by 43.4 and 51.5%, respectively. At the same time, the heat transfer coefficient of the ETB and its growth rate decrease by 3.9 and 45.6%. Additionally, the baffle curvature has little impact on the vibration and heat transfer performance. The difference between the average heat transfer coefficient and the total vibration amplitude of the ETB for different baffle curvatures is less than 5%.
{"title":"Vibration and Heat Transfer Study on Elastic-Tube Heat Exchange with Curved Baffle","authors":"Qie Xiwang, Ji Jiadong, Li Feiyang, Deng Xu, Zhou Jianxin","doi":"10.2514/1.t6816","DOIUrl":"https://doi.org/10.2514/1.t6816","url":null,"abstract":"A heat exchanger with a curved baffle for an elastic-tube bundle (ETB) is designed to effectively improve the performance based on a common ETB heat exchanger, and this paper systematically studies its vibration and heat transfer characteristics under different inlet velocity and structural parameters. The results indicate that the ETB vibration characteristics increase significantly with an increasing velocity, and the average amplitude of the ETB at [Formula: see text] is 4.51 times higher than that at [Formula: see text]. Similarly, the heat transfer performance subsequently decreases, but the average heat transfer coefficient of the ETB is significantly increased with the increase of the inlet velocity. When the long axis increases from 45 to 75 mm, the vibration intensity of the ETB decreases sharply, and the [Formula: see text] direction and the total vibration [Formula: see text] decrease by 43.4 and 51.5%, respectively. At the same time, the heat transfer coefficient of the ETB and its growth rate decrease by 3.9 and 45.6%. Additionally, the baffle curvature has little impact on the vibration and heat transfer performance. The difference between the average heat transfer coefficient and the total vibration amplitude of the ETB for different baffle curvatures is less than 5%.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135590848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ablation of carbon cloth phenolic insulators used in solid rocket motor (SRM) nozzles involves highly complex phenomena that are difficult to accurately predict. Historical and even more modern ablation predictions rely heavily on anchoring to SRM test data to improve predictability and SRM reliability. Accelerated schedules, reductions in static SRM testing prior to flight, and a highly competitive global market are placing a substantial onus on computational capability and predictive uncertainty. Quantifying uncertainty in SRM nozzle ablation predictions is essential for motor reliability. This paper provides the details of a modern uncertainty quantification methodology applied to ablation predictions in carbon cloth phenolic insulators exposed to SRM nozzle environments. A particular historical test motor is used as a demonstration case. The system response quantities of interest are the erosion depth and char depth. A representative model and input uncertainty are provided, and a sensitivity analysis is performed to identify influential parameters. Uncertainties in the numerical models and inputs are propagated through a two-dimensional uncertainty quantification methodology using a Latin Hypercube Sampling approach. The results show that the primary sources of uncertainty in SRM nozzle thermal modeling are the heat transfer coefficient, incident radiation heat flux, char material thermal conductivity, virgin material density, char material density, char material specific heat, and pyrolysis gas enthalpy. Uncertainties in the predictions of nozzle insulation erosion and char for the test case are provided relative to the nozzle location at the 99 th percentile and 95th confidence interval. Uncertainty in the char depth is roughly [Formula: see text] along the entire axial length of the nozzle. Uncertainty in the erosion depth ranges from about [Formula: see text] for the entrance and throat regions to [Formula: see text] at the nozzle exit.
{"title":"Uncertainty in Modeling Ablation Heat Transfer in Rocket Nozzles","authors":"Bradley Heath, Mark Ewing","doi":"10.2514/1.t6856","DOIUrl":"https://doi.org/10.2514/1.t6856","url":null,"abstract":"The ablation of carbon cloth phenolic insulators used in solid rocket motor (SRM) nozzles involves highly complex phenomena that are difficult to accurately predict. Historical and even more modern ablation predictions rely heavily on anchoring to SRM test data to improve predictability and SRM reliability. Accelerated schedules, reductions in static SRM testing prior to flight, and a highly competitive global market are placing a substantial onus on computational capability and predictive uncertainty. Quantifying uncertainty in SRM nozzle ablation predictions is essential for motor reliability. This paper provides the details of a modern uncertainty quantification methodology applied to ablation predictions in carbon cloth phenolic insulators exposed to SRM nozzle environments. A particular historical test motor is used as a demonstration case. The system response quantities of interest are the erosion depth and char depth. A representative model and input uncertainty are provided, and a sensitivity analysis is performed to identify influential parameters. Uncertainties in the numerical models and inputs are propagated through a two-dimensional uncertainty quantification methodology using a Latin Hypercube Sampling approach. The results show that the primary sources of uncertainty in SRM nozzle thermal modeling are the heat transfer coefficient, incident radiation heat flux, char material thermal conductivity, virgin material density, char material density, char material specific heat, and pyrolysis gas enthalpy. Uncertainties in the predictions of nozzle insulation erosion and char for the test case are provided relative to the nozzle location at the 99 th percentile and 95th confidence interval. Uncertainty in the char depth is roughly [Formula: see text] along the entire axial length of the nozzle. Uncertainty in the erosion depth ranges from about [Formula: see text] for the entrance and throat regions to [Formula: see text] at the nozzle exit.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135816274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kelvin Guessi Domiciano, Larissa Krambeck, Marcia Barbosa Henriques Mantelli, Luis Alonso Betancur Arboleda
Two flat plate diffusion-bonded pulsating heat pipes (PHPs) for the thermal management and heat dissipation of concentrated heat flux in electronics applications, such as aboard satellites and spacecraft, were specially developed for future tests aboard a sounding rocket in microgravity conditions. Both devices contain 26 channels with round cross sections, one with ultrasharp lateral grooves in the evaporator. Two heat sinks were tested: a water-cooling bath for the thermal characterization of the PHPs, and a copper box with a phase change material (dodecahydrate bibasic sodium phosphate) to be qualified as the heat storage for future microgravity tests. Water was used as the working fluid. The best filling ratio (relative to the total internal volume of the PHPs) was experimentally determined to be 50%, for which the devices presented the earliest startup and the lowest thermal resistance, around 0.033°C/W for the grooved PHP. This research proposes an efficient and alternative cooling method, the phase change material storage, to be used as a heat sink in future microgravity tests. Also, the microgravity effect on the thermal performance of such PHPs can be assessed by comparing the present results with future microgravity data obtained in an experimental module aboard a sounding rocket.
{"title":"Pulsating Heat Pipe Experiments for Microgravity Sounding Rocket Tests","authors":"Kelvin Guessi Domiciano, Larissa Krambeck, Marcia Barbosa Henriques Mantelli, Luis Alonso Betancur Arboleda","doi":"10.2514/1.t6826","DOIUrl":"https://doi.org/10.2514/1.t6826","url":null,"abstract":"Two flat plate diffusion-bonded pulsating heat pipes (PHPs) for the thermal management and heat dissipation of concentrated heat flux in electronics applications, such as aboard satellites and spacecraft, were specially developed for future tests aboard a sounding rocket in microgravity conditions. Both devices contain 26 channels with round cross sections, one with ultrasharp lateral grooves in the evaporator. Two heat sinks were tested: a water-cooling bath for the thermal characterization of the PHPs, and a copper box with a phase change material (dodecahydrate bibasic sodium phosphate) to be qualified as the heat storage for future microgravity tests. Water was used as the working fluid. The best filling ratio (relative to the total internal volume of the PHPs) was experimentally determined to be 50%, for which the devices presented the earliest startup and the lowest thermal resistance, around 0.033°C/W for the grooved PHP. This research proposes an efficient and alternative cooling method, the phase change material storage, to be used as a heat sink in future microgravity tests. Also, the microgravity effect on the thermal performance of such PHPs can be assessed by comparing the present results with future microgravity data obtained in an experimental module aboard a sounding rocket.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135817080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hendrik Burghaus, Clemens F. Kaiser, Adam S. Pagan, Stefanos Fasoulas, Georg Herdrich
This paper describes the application of tunable diode laser absorption spectroscopy to a high-power supersonic carbon dioxide plasma, which is relevant for Mars entry. The measurements are complemented by optical emission spectroscopy and intrusive probe diagnostics. The experiments are performed in the PWK3 plasma wind tunnel, powered by the IPG4 inductive plasma generator. An infrared diode laser is tuned by a frequency generator targeting the atomic oxygen triplet at 844 nm. Radial measurements of the plasma jet are conducted at an axial distance of 105 mm from the nozzle exit. The absorption data are corrected for the laser baseline and for oscillations induced by the vacuum pumps. On the plasma jet centerline, a temperature of [Formula: see text] and an excited state number density of [Formula: see text] are determined by analyzing the isolated [Formula: see text] absorption profile. A centerline mass-specific enthalpy of [Formula: see text] is estimated by assuming thermochemical equilibrium inside the plasma generator, followed by isentropic expansion of the flow. In consideration of the uncertainties, this agrees well with the value of [Formula: see text] determined based on intrusive probe measurements.
{"title":"Aerothermodynamic Characterization of Inductively Generated Carbon Dioxide Plasma by Laser Absorption Spectroscopy","authors":"Hendrik Burghaus, Clemens F. Kaiser, Adam S. Pagan, Stefanos Fasoulas, Georg Herdrich","doi":"10.2514/1.t6831","DOIUrl":"https://doi.org/10.2514/1.t6831","url":null,"abstract":"This paper describes the application of tunable diode laser absorption spectroscopy to a high-power supersonic carbon dioxide plasma, which is relevant for Mars entry. The measurements are complemented by optical emission spectroscopy and intrusive probe diagnostics. The experiments are performed in the PWK3 plasma wind tunnel, powered by the IPG4 inductive plasma generator. An infrared diode laser is tuned by a frequency generator targeting the atomic oxygen triplet at 844 nm. Radial measurements of the plasma jet are conducted at an axial distance of 105 mm from the nozzle exit. The absorption data are corrected for the laser baseline and for oscillations induced by the vacuum pumps. On the plasma jet centerline, a temperature of [Formula: see text] and an excited state number density of [Formula: see text] are determined by analyzing the isolated [Formula: see text] absorption profile. A centerline mass-specific enthalpy of [Formula: see text] is estimated by assuming thermochemical equilibrium inside the plasma generator, followed by isentropic expansion of the flow. In consideration of the uncertainties, this agrees well with the value of [Formula: see text] determined based on intrusive probe measurements.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134989961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work investigates the combined mode of hyperbolic heat conduction and radiation transfer in a one-dimensional axisymmetric cylinder filled with absorbing, emitting, and scattering media. The volumetric radiation is investigated thanks to the semianalytic solution of the matrix formulation of the spherical harmonics equations [Formula: see text]. The governing hyperbolic energy equation is solved using the finite volume method (FVM) with Roe’s correction of interface fluxes in order to enhance the performances of the method, and the lattice Boltzmann method (LBM) has been designed for comparisons. The effects of the parameters such as constant and spatial-dependent scattering albedos, temperature-dependent thermal conductivity, heat-generated sources, extinction, and the conduction–radiation parameter on both the temperature and heat flux distributions for steady and transient states within the medium are examined. The results of the present work are in excellent agreement with those available in the literature. The [Formula: see text] results are also compared to those obtained with the [Formula: see text] combination, and excellent agreement is obtained. These results show that the mentioned parameters have a significant effect on both the temperature profiles and the hyperbolic sharp wave front. This study also shows that the proposed layered approach is an efficient, fast, and accurate solution method for radiative analysis in inhomogeneous media, whereas the Roe’s correction of interface fluxes in the FVM is suitable to accommodate a thermal wave front in non-Fourier analysis.
{"title":"Hyperbolic Conduction and Radiation Heat Transfer in Axisymmetric Cylinders with Variable Properties","authors":"Guillaume Lambou Ymeli","doi":"10.2514/1.t6859","DOIUrl":"https://doi.org/10.2514/1.t6859","url":null,"abstract":"This work investigates the combined mode of hyperbolic heat conduction and radiation transfer in a one-dimensional axisymmetric cylinder filled with absorbing, emitting, and scattering media. The volumetric radiation is investigated thanks to the semianalytic solution of the matrix formulation of the spherical harmonics equations [Formula: see text]. The governing hyperbolic energy equation is solved using the finite volume method (FVM) with Roe’s correction of interface fluxes in order to enhance the performances of the method, and the lattice Boltzmann method (LBM) has been designed for comparisons. The effects of the parameters such as constant and spatial-dependent scattering albedos, temperature-dependent thermal conductivity, heat-generated sources, extinction, and the conduction–radiation parameter on both the temperature and heat flux distributions for steady and transient states within the medium are examined. The results of the present work are in excellent agreement with those available in the literature. The [Formula: see text] results are also compared to those obtained with the [Formula: see text] combination, and excellent agreement is obtained. These results show that the mentioned parameters have a significant effect on both the temperature profiles and the hyperbolic sharp wave front. This study also shows that the proposed layered approach is an efficient, fast, and accurate solution method for radiative analysis in inhomogeneous media, whereas the Roe’s correction of interface fluxes in the FVM is suitable to accommodate a thermal wave front in non-Fourier analysis.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41729074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forced jet mixing with and without cooling has long been proposed for active pressure control of cryogenic tanks in microgravity. In this paper, a three-dimensional two-phase computational fluid dynamics (CFD) model is presented that was developed to capture the intricate dynamic interaction between a forced liquid jet and the ullage interface under weightlessness conditions. The CFD model is validated against the microgravity results of the Tank Pressure Control Experiment. The volume-of-fluid method is used to capture the ullage deformation as well as movement in the jet mixing simulations of the microgravity experiment. Two different initial ullage positions are considered, and computational results for the jet–ullage interaction are compared with a still-image sequence captured from real-time video of the experiment. Parametric simulations over a range of jet Weber numbers indicate four distinct jet–ullage interaction modes from nonpenetrating to fully penetrating, which are corroborated experimentally. Qualitative comparisons also provide good agreement between CFD predictions and experimental results with regard to the main features of the ullage dynamics, such as movement, deformation, and jet penetration during microgravity mixing.
{"title":"Computational Fluid Dynamics Analysis of Jet-Ullage Interactions During Microgravity Mixing","authors":"Olga Kartuzova, Mohammad Kassemi","doi":"10.2514/1.t6725","DOIUrl":"https://doi.org/10.2514/1.t6725","url":null,"abstract":"Forced jet mixing with and without cooling has long been proposed for active pressure control of cryogenic tanks in microgravity. In this paper, a three-dimensional two-phase computational fluid dynamics (CFD) model is presented that was developed to capture the intricate dynamic interaction between a forced liquid jet and the ullage interface under weightlessness conditions. The CFD model is validated against the microgravity results of the Tank Pressure Control Experiment. The volume-of-fluid method is used to capture the ullage deformation as well as movement in the jet mixing simulations of the microgravity experiment. Two different initial ullage positions are considered, and computational results for the jet–ullage interaction are compared with a still-image sequence captured from real-time video of the experiment. Parametric simulations over a range of jet Weber numbers indicate four distinct jet–ullage interaction modes from nonpenetrating to fully penetrating, which are corroborated experimentally. Qualitative comparisons also provide good agreement between CFD predictions and experimental results with regard to the main features of the ullage dynamics, such as movement, deformation, and jet penetration during microgravity mixing.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135320210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the rapid development of vacuum tube transport technology, there is increased interest in understanding the behavior of the heat transfer of rarefied gas in a vacuum tube. Currently, most empirical correlations of forced convection heat transfer are conducted at the standard atmospheric pressure, so many correlations are not applicable to conditions below the atmospheric pressure. To investigate the heat transfer property under low-pressure conditions, the forced convection between isothermal plate and air in a low-pressure environment is numerically simulated. The results show that the traditional correlation of the forced convection heat transfer between the isothermal plate and gases is different from the actual results at low pressure, and the correlation is completely invalid when the pressure is lower than 0.2 kPa. Based on the data of numerical calculation, a modified correlation of forced convection heat transfer between an isothermal plate and gases under low pressure is proposed. The correlation coefficient [Formula: see text] is greater than 0.99, and the fitting error is less than 10% at the 95% confidence level. The change of heat transfer depends on the Reynolds number in the pressure range of 0.2–100 kPa, but the effect of Reynolds number is weakened and the effect of pressure is strengthened when the pressure is below 0.2 kPa.
{"title":"Correlation of Forced Convection Heat Transfer of Isothermal Plate Under Low Pressure","authors":"Tianjun Luo, Yanjun Chen, Deqiang He, Yongli Chen","doi":"10.2514/1.t6846","DOIUrl":"https://doi.org/10.2514/1.t6846","url":null,"abstract":"With the rapid development of vacuum tube transport technology, there is increased interest in understanding the behavior of the heat transfer of rarefied gas in a vacuum tube. Currently, most empirical correlations of forced convection heat transfer are conducted at the standard atmospheric pressure, so many correlations are not applicable to conditions below the atmospheric pressure. To investigate the heat transfer property under low-pressure conditions, the forced convection between isothermal plate and air in a low-pressure environment is numerically simulated. The results show that the traditional correlation of the forced convection heat transfer between the isothermal plate and gases is different from the actual results at low pressure, and the correlation is completely invalid when the pressure is lower than 0.2 kPa. Based on the data of numerical calculation, a modified correlation of forced convection heat transfer between an isothermal plate and gases under low pressure is proposed. The correlation coefficient [Formula: see text] is greater than 0.99, and the fitting error is less than 10% at the 95% confidence level. The change of heat transfer depends on the Reynolds number in the pressure range of 0.2–100 kPa, but the effect of Reynolds number is weakened and the effect of pressure is strengthened when the pressure is below 0.2 kPa.","PeriodicalId":17482,"journal":{"name":"Journal of Thermophysics and Heat Transfer","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42463865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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