Journal of Propulsion and Power最新文献_第10页

Assessment of Pseudoshock Models Against Experiment in a Low-Aspect-Ratio Isolator 低展弦比隔离器中伪激波模型的试验评估

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-06-10 DOI: 10.2514/1.b38913

Louis M. Edelman, M. Gamba, Robin L. Hunt, A. Auslender

{"title":"Assessment of Pseudoshock Models Against Experiment in a Low-Aspect-Ratio Isolator","authors":"Louis M. Edelman, M. Gamba, Robin L. Hunt, A. Auslender","doi":"10.2514/1.b38913","DOIUrl":"https://doi.org/10.2514/1.b38913","url":null,"abstract":"A highly confined shock train is investigated in a direct-connect isolator facility with a Mach 2 inflow and a constant-area low-aspect-ratio rectangular test section. High-speed schlieren imaging, wall static pressure measurements, surface oil-flow visualization, and particle image velocimetry from this isolator are synthesized into a three-dimensional schematic of the shock train structure. Against this, the prevailing pseudoshock models in the literature are assessed to evaluate the validity of their underlying assumptions. None of the prevailing pseudoshock models are found to simultaneously model the pressure and Mach number profiles, indicating a gap in the model formation and underlying assumptions when applied to the experimental isolator of interest. The presence of distortion in the isolator flowfield, such as a wall-bounded vortex, is found to skew the structure of the shock train, altering the strength and distribution of the compressive pressure gradient. It is further observed that the separated flow morphology surrounding the shock train is not monolithic, as is typically assumed, adjusting the balance of compressive forces within the shock cells. These findings lead to the conclusion that existing flux-conserved modeling approaches require modification to be effective in distorted and highly confined cases, including closure models that capture the three-dimensional distorted structure of the approach flow and its evolution along the shock train.","PeriodicalId":16903,"journal":{"name":"Journal of Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44522288","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}

引用次数: 0

Observation of Plasma Turbulence in a Hall Thruster Using Microwave Interferometry 用微波干涉法观察霍尔推力器中的等离子体湍流

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-06-05 DOI: 10.2514/1.b38711

N. Yamamoto, Naoya Kuwabara, D. Kuwahara, Shinatora Cho, Y. Kosuga, Guilhem Dif Pradalier

{"title":"Observation of Plasma Turbulence in a Hall Thruster Using Microwave Interferometry","authors":"N. Yamamoto, Naoya Kuwabara, D. Kuwahara, Shinatora Cho, Y. Kosuga, Guilhem Dif Pradalier","doi":"10.2514/1.b38711","DOIUrl":"https://doi.org/10.2514/1.b38711","url":null,"abstract":"To understand anomalous electron transport in a Hall thruster, plasma turbulence inside the acceleration channel was observed using a 76 GHz microwave interferometer. The dependence of the amplitude of the 100–500 kHz turbulence on magnetic flux density, and the relationships between the turbulence and other plasma instabilities and between the turbulence and the discharge current were investigated through spectral density and bicoherence analysis. The amplitude of electron number density fluctuations of the turbulence, integrating the spectral density from 100 to 500 kHz, is [Formula: see text], or almost 10% of the time-averaged electron number density. The amplitude of the turbulence decreases with increase in weak magnetic field strength (coil current less than 0.6 A) and then increases with increase in magnetic field strength. The amplitude of the turbulence has a positive relation to the discharge current, leads to anomalous electron transport inside the acceleration channel, and is coupled with ionization instability. In addition, low-frequency perturbations of several hundred hertz were observed, with a positive relation to the turbulence and coupled with both ionization instability and turbulence.","PeriodicalId":16903,"journal":{"name":"Journal of Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47766074","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}

引用次数: 0

Multiphase Effects on Solid Rocket Nozzle Performance 多相效应对固体火箭喷嘴性能的影响

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-26 DOI: 10.2514/1.b39096

M. Grossi, Alessio Sereno, D. Bianchi, B. Favini

引用次数: 0

Deflagration to Detonation Transition in Heterogeneous Mixtures Containing Ethanol/Acetone and Oxygen 含乙醇/丙酮和氧气的非均质混合物的爆燃-爆轰转变

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-26 DOI: 10.2514/1.b39154

H. Kadosh, D. Michaels

{"title":"Deflagration to Detonation Transition in Heterogeneous Mixtures Containing Ethanol/Acetone and Oxygen","authors":"H. Kadosh, D. Michaels","doi":"10.2514/1.b39154","DOIUrl":"https://doi.org/10.2514/1.b39154","url":null,"abstract":"Liquid fuel is the choice for volume-limited propulsion systems, including detonation-based propulsion. A liquid fuel with high vapor pressure has the advantage of more fuel vapor in the mixture, which supports the transition from deflagration to detonation. This paper reports on an experimental study of deflagration-to-detonation transition (DDT) in a pulse detonation engine with heterogenous mixtures of oxygen and ethanol or acetone. Single-cycle tests were taken for different fuels, equivalence ratios, and DDT enhancement methods. The size distribution of fuel droplets was characterized at the atomizer and engine exit. The effect of the fuel evaporation was dominant for the acetone spray only. Comparing the measured detonation velocities of the two mixtures, a lower velocity deficit relative to the theoretical Chapman–Jouguet detonation velocity was measured for the acetone–oxygen mixtures, and this behavior is related to the higher amount of fuel vapor that existed in the mixtures. Moreover, a shorter transition to detonation was observed in the acetone–oxygen mixture. The addition of a Shchelkin spiral reduced the DDT distance; however, the Chapman–Jouguet condition could be reached only downstream of the obstacle. The measured detonation cell size of the heterogeneous acetone–oxygen mixture was smaller than that of the ethanol–oxygen mixture, indicating that it is more detonable.","PeriodicalId":16903,"journal":{"name":"Journal of Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44185231","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}

引用次数: 0

Experimental Characterization of a Hollow Cathode with Iridium–Cerium Alloy 铱铈合金空心阴极的实验表征

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-26 DOI: 10.2514/1.b38511

Hiroki Watanabe, Shinatora Cho, Yoshiki Matsunaga, Yasushi Ohkawa, Yu Tao, Fumiaki Kudo, K. Koga, Satoshi Yabu

引用次数: 0

Long-Duration Test of Coaxial Low-Energy Surface Flashover Ignitor 同轴低能量表面闪络点火器的长时间试验

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-21 DOI: 10.2514/1.b39071

Yunping Zhang, Lee Organski, A. Shashurin, K. Ostrikov

引用次数: 0

Regression and Flame Structure in Cavity Flameholding Solid-Fuel Ramjet Fuel Grains 空腔火焰保持固体燃料冲压发动机燃料颗粒的回归与火焰结构

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-17 DOI: 10.2514/1.b39139

Dominic Gallegos, Henry Pace, Charles Arnold, L. Massa, Greg Young

{"title":"Regression and Flame Structure in Cavity Flameholding Solid-Fuel Ramjet Fuel Grains","authors":"Dominic Gallegos, Henry Pace, Charles Arnold, L. Massa, Greg Young","doi":"10.2514/1.b39139","DOIUrl":"https://doi.org/10.2514/1.b39139","url":null,"abstract":"Introducing cavity flameholders into a solid-fuel ramjet fuel grain demonstrated increased fuel loading with sustained combustion in previously unfavorable geometries. Volumetric fuel loading improvements of up to 26% were demonstrated to sustain combustion. Regression patterns of cavity fuel grains are presented and show that the effect of implementing a cavity flameholder is to change the location of maximum regression and the reattachment point. The addition of a cavity flameholder does not appear to have a significant effect on combustion efficiency. However, it is noteworthy that longer cavities increased the chamber pressure above what was observed for a center-perforated fuel grains as a result of the increased mass addition and higher equivalence ratio associated with the higher regression rate. Large-eddy simulation computations were performed using a fourth-order discontinuous Galerkin finite element solver with a novel flamelet and progress variable formulation. The predictions agree well with the experiments and point to the increased heat transfer for longer cavities as the main flameholder mechanism. The larger heat feedback is supported by the formation of a stronger recirculation region, which leads to increased coherent fluctuations due to the transition between local and global instabilities.","PeriodicalId":16903,"journal":{"name":"Journal of Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41865905","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}

引用次数: 0

Low-Order Autoignition Modeling for Hydrogen Transverse Jets 氢横向射流的低阶自燃模型

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-04 DOI: 10.2514/1.b39142

S. Gkantonas, E. Mastorakos

{"title":"Low-Order Autoignition Modeling for Hydrogen Transverse Jets","authors":"S. Gkantonas, E. Mastorakos","doi":"10.2514/1.b39142","DOIUrl":"https://doi.org/10.2514/1.b39142","url":null,"abstract":"This paper presents a method for evaluating the risk of autoignition for the canonical problem of an enclosed hydrogen jet in crossflow (JICF), which is highly relevant to the design of mixing ducts. The proposed method is based on the separation of the underlying mixing pattern from the evolution of the chemical reactions, whereas the effect of mixing is maintained on the latter with the purpose of creating a reliable yet computationally efficient design tool for hydrogen gas turbines. Two variants of the incompletely stirred reactor network (ISRN) approach are proposed that provide the evolution of preignition radicals and autoignition kernel location, leveraging a nonreacting computational fluid dynamics solution or an analytical mixing pattern. The ISRN governing equations include all the salient features of hydrogen transport and lead to a conservative estimate of autoignition risk. Application to a few model problems with varied operating conditions suggests that radical buildup in the JICF can lead to autoignition in the vicinity of a most reactive mixture fraction, which is consistent with other laminar or turbulent hydrogen flows. However, the radical formation and autoignition kernel location strongly depend on the prediction of the underlying mixing field and the amount of differential diffusion within the JICF, which here primarily favors lower values of the composite mixture fraction and the transport of hydrogen and radicals away from the jet trajectory.","PeriodicalId":16903,"journal":{"name":"Journal of Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45467165","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}

引用次数: 0

Design of an Internal Osculating Waverider Intake 内啮合乘波器进气口设计

4区工程技术

Journal of Propulsion and Power Pub Date : 2023-05-01 DOI: 10.2514/1.b38916

Mark E. Noftz, Andrew J. Shuck, Joseph S. Jewell, Jonathan Poggie, Andrew N. Bustard, Thomas J. Juliano, Nicholas J. Bisek

引用次数: 3

Bicyclo-HMX as an Energetic Additive for Composite Propellants 双环hmx作为复合推进剂的高能添加剂

IF 1.9 4区工程技术

Journal of Propulsion and Power Pub Date : 2023-04-16 DOI: 10.2514/1.b38977

Filip Sazeček, Ondřej Vodochodský, R. Matyáš, Petr Stojan, J. Zigmund, J. Pachman

引用次数: 0