Multiple Chambers Research Articles

Dynamic evolution of arc plasma in a semi-enclosed arc-extinguishing chamber and its influencing factors

Multi-chamber arc-extinguishing has been widely researched and used to protect transmission and distribution lines from lightning. Its principle is to divide a long-gap arc into multiple short-gap arcs using multiple semi-enclosed arc-extinguishing chambers. To study the dynamic evolution of arc plasma in an arc-extinguishing chamber, we establish a three-dimensional simulation model of arc plasma in a semi-enclosed arc-extinguishing chamber by solving the Navier–Stokes and Maxwell equations. We analyze the dynamic evolution of an arc from the inside of the chamber to the outside. An impact current test platform is built and the arc motion is photographed by a high-speed camera, revealing the acceleration of the arc in the semi-enclosed chamber. Finally, the influence of chamber dimensions on key arc parameters is analyzed. In the simulation, the time when the arc completely moves out of the chamber and is extinguished is consistent with the experimental images, which verifies the accuracy of the simulation model. The arc temperature, chamber pressure, and airflow velocity first increase in an oscillating manner and then slowly decrease with time. The change of the opening diameter will lead to the obvious change of the arc temperature maximum. The opening diameter is the main chamber dimension that affects the arc temperature. The electrode spacings have the most obvious effect on the maximum pressure in the chamber. The minimum pressure in different chamber dimensions is lower than the atmospheric pressure. The influence of opening diameter, distance from central axis to closed side, and opening wall length on the maximum airflow velocity is the same, and the maximum airflow velocity decreases with the increase in these dimensions. The influence of electrode spacing on the maximum airflow velocity is opposite to them.

A Data-Driven Predictive Machine Learning Model for Efficiently Storing Temperature-Sensitive Medical Products, Such as Vaccines: Case Study: Pharmacies in Rwanda.

Temperature control is the key element during medicine storage. Pharmacies sell some medical products which are kept in fridges. The opening and closing of the fridge while taking some medicine makes the outside hot air enter the fridge, which will increase the inner fridge temperature. When the frequency of opening and closing of the fridge is increased, the temperature may go beyond the allowed storage temperature range. In this paper, we are proposing a model with the help of machine learning that will be used in multiple chambers fridges to keep indicating the time remaining for the inner temperature to go beyond the allowed range, and if the time is short, the system will propose to the pharmacist not to open that particular room and proposes a room that has enough time slots (time to reach the upper limit temperature). By using training data got from a thermoelectric cooler-based fridge, we constructed a multiple linear regression model that can predict the required time for a given room to reach the cut-off temperature in case that room is opened. The built model was evaluated using the coefficient of determination R2 and is found to be 77%, and then it can be used to develop a multiple room smart fridge for efficiently storing highly sensitive medical products.

Assessment of the factors affecting the weathering properties of Pigment Yellow 74 in decorative paint

AbstractColor or shade fading is one of the major issues observed in decorative paints. Here we have carried out a systematic artificial weathering study using QUV and ATLAS weathering test chambers for Pigment Yellow 74 (PY 74). Pigment dispersion of PY 74 received from three different manufacturers are prepared. Various factors, such as the processing parameter, for example, grinding temperature (with and without cooling water circulation during the processing of pigment dispersion), with respect to paints the factors such as primers and clear base paints of different batches, and as for the ATLAS and QUV weatherability test concerned, test panels of different lots, and multiple QUV chambers are evaluated. The color difference was recorded at regular time intervals for the panels exposed to ATLAS and QUV test of 1000 hours using color spectrophotometer. A significant color difference was recorded for the panels coated with paints based on pigment dispersion prepared using PY 74 from different manufacturers, and the difference in grinding temperature. These results show the importance of process parameters such as grinding temperature on weathering properties, and systematic testing approaches for QUV/ATLAS for the pigments from different manufacturers.

Differential Throttling and Fluidic Thrust Vectoring in a Linear Aerospike

Aerospike nozzles represent an interesting solution for Single-Stage-To-Orbit or clustered launchers owing to their self-adapting capability, which can lead to better performance compared to classical nozzles. Furthermore, they can provide thrust vectoring in several ways. A simple solution consists of applying differential throttling when multiple combustion chambers are used. An alternative solution is represented by fluidic thrust vectoring, which requires the injection of a secondary flow from a slot. In this work, the flow field in a linear aerospike nozzle was investigated numerically and both differential throttling and fluidic thrust vectoring were studied. The flow field was predicted by solving the Reynolds-averaged Navier–Stokes equations. The thrust vectoring performance was evaluated in terms of side force generation and axial force reduction. The effectiveness of fluidic thrust vectoring was investigated by changing the mass flow rate of secondary flow and injection location. The results show that the response of the system can be non-monotone with respect to the mass flow rate of the secondary injection. In contrast, differential throttling provides a linear behaviour but it can only be applied to configurations with multiple combustion chambers. Finally, the effects of different plug truncation levels are discussed.

Automated cardiac volume assessment and cardiac long- and short-axis imaging plane prediction from electrocardiogram-gated computed tomography volumes enabled by deep learning.

AimsTo develop an automated method for bloodpool segmentation and imaging plane re-slicing of cardiac computed tomography (CT) via deep learning (DL) for clinical use in coronary artery disease (CAD) wall motion assessment and reproducible longitudinal imaging.Methods and resultsOne hundred patients who underwent clinically indicated cardiac CT scans with manually segmented left ventricle (LV) and left atrial (LA) chambers were used for training. For each patient, long-axis (LAX) and short-axis planes were manually defined by an imaging expert. A DL model was trained to predict bloodpool segmentations and imaging planes. Deep learning bloodpool segmentations showed close agreement with manual LV [median Dice: 0.91, Hausdorff distance (HD): 6.18 mm] and LA (Dice: 0.93, HD: 7.35 mm) segmentations and a strong correlation with manual ejection fraction (Pearson r: 0.95 LV, 0.92 LA). Predicted planes had low median location (6.96 mm) and angular orientation (7.96) errors which were comparable to inter-reader differences (P > 0.71). 84–97% of DL-prescribed LAX planes correctly intersected American Heart Association segments, which was comparable (P > 0.05) to manual slicing. In a test cohort of 144 patients, we evaluated the ability of the DL approach to provide diagnostic imaging planes. Visual scoring by two blinded experts determined ≥94% of DL-predicted planes to be diagnostically adequate. Further, DL-enabled visualization of LV wall motion abnormalities due to CAD and provided reproducible planes upon repeat imaging.ConclusionA volumetric, DL approach provides multiple chamber segmentations and can re-slice the imaging volume along standardized cardiac imaging planes for reproducible wall motion abnormality and functional assessment.

One-step double emulsion via amphiphilic Se[sbnd]N supramolecular interactions: Towards porous multi-cavity beads for efficient recovery lithium from brine

Efficient recovery lithium ions (Li+) from brine is a recognized challenge with potential strategic and economic implications. In this work, one-step double emulsion reactors, based on amphiphilic SeN supramolecular interactions between phenyl selenium bromide (PhSeBr) and polystyrene-b-polyvinylpyridine (PS-b-P4VP), was constructed to prepare porous multi-cavity beads (PMCB). After immobilizing aminoethyl benzo-12-crown-4 (B12C4-NH2) through post-interface modification strategy, the resultant sorbents (PMCB-B12C4) were adopted for selective separation and enrichment Li+ from brine. PMCB-B12C4 possessed surface pores, multiple interconnected chambers, and abundant crown ether receptors, and the dynamic and adjustable mechanism between structure and turning the volume fraction was also studied. Li+ adsorption in PMCB-B12C4 is best approximated by Langmuir and Hill isotherms showing the homogeneous adsorption on the heterogeneous surface, and the calculated maximum monolayer adsorption capacities are 61.35 mg g−1 and 59.53 mg g−1, respectively. Kinetic study reveals good agreement by pseudo-second order, and chemical adsorption mainly dominates the adsorption process. The mass transfer study depicts that both membrane and inter-particle diffusion are involved in a diffusion inhibition rate process. PMCB-B12C4 can selectively recovery Li+ from simulated samples with the selectivity coefficient (α) and relative selectivity coefficient (αr) as high as >5.0 and 6.0, respectively. PMCB-B12C4 still retains significant Li+ uptake capacity in brine owing to the specific “size matching” effect of crown ether. Moreover, PMCB-B12C4 is regenerated in mild acid and exhibits nearly consistent adsorption capacity after five reuse cycles. Thus, this work not only reports a new clue to fabricate porous sorbent beads via droplet reactor, but also provides a novel platform for Li+ extraction.

Editor's comments

Most of the more than one million cardiac pacemakers implanted each year have up to three leads that reach into the heart's chambers. The most modern pacemakers integrate all of the pacemaker functions into a small capsule that be directly implanted into the endocardium, resulting in what is known as a leadless cardiac pacemaker. However, these can typically only be used to stimulate a single chamber. By using intra-body communication, the operation of more than one leadless cardiac pacemaker can be synchronized, resulting in the ability to use this approach with multiple chambers of the heart. The paper by Mirko Maldari, Chadi Jabbour, Youcef Haddab, and Patricia Desgreys describes a system for such intra-body communication for pacemakers. The design and development of the system is described, as well as the optimization of the power usage of the system based on the signal waveform involved. The results demonstrated the telemetry-based synchronization of a dual-chamber leadless cardiac pacemaker system with minimum power consumption. This paper was based on one of the finalists for the 2021 URSI-France PhD Prize in Radio Science.

Continuous online monitoring of ice-nucleating particles: development of the automated Horizontal Ice Nucleation Chamber (HINC-Auto)

Abstract. The incomplete understanding of aerosol–cloud interactions introduces large uncertainties when simulating the cloud radiative forcing in climate models. The physical and optical properties of a cloud, as well as the evolution of precipitation, are strong functions of the cloud hydrometeor phase. Aerosol particles support the phase transition of water in the atmosphere from a meta-stable to a thermodynamically preferred stable phase. In the troposphere, the transition of liquid droplets to ice crystals in clouds, via ice-nucleating particles (INPs) which make up only a tiny fraction of all tropospheric aerosol, is of particular relevance. For accurate cloud modeling in climate projections, the parameterization of cloud processes and information such as the concentrations of atmospheric INPs are needed. Presently, only few continuous real-time INP counters are available and the data acquisition often still requires a human operator. To address this restriction, we developed HINC-Auto, a fully automated online INP counter, by adapting an existing custom-built instrument, the Horizontal Ice Nucleation Chamber. HINC-Auto was able to autonomously sample INPs in the immersion mode at a temperature of 243 K and a water saturation ratio of 1.04 for 97 % of the time for 90 consecutive days. Here, we present the technical setup used to acquire automation, discuss improvements to the experimental precision and sampling time, and validate the instrument performance. In the future, the chamber will allow a detailed temporal analysis (including seasonal and annual variability) of ambient INP concentrations observing repeated meteorological phenomena compared to previous episodic events detected during campaigns. In addition, by deploying multiple chambers at different locations, a spatiotemporal variability of INPs at any sampling site used for monitoring INP analysis can be achieved for temperatures ≤ 243 K.

System Analysis and Reliability Analysis for Environmental Test Chambers

The purpose of this paper is to present the results of the application of various models to estimate the reliability of environmental test chambers, especially, the methodology proposed by the International Electrotechnical Commission (IEC), using the Homogeneous Poisson process (HPP) and Non-Homogeneous Poisson process (NHPP) models, is adopted first, and then, a non-monotonic trend test and bathtub curve intensity function not covered by IEC are used, and supplementary analysis is used to characterize the resulting failure intensity. For the first time, the stochastic process model was applied to evaluate the reliability of 20 environmental test chambers. The results show that the IEC standards process is suitable for the reliability evaluation of a single chamber, and 16 chambers conform to the HPP model and 4 chambers conform to the NHPP model. However, there is the power-law model (PLP) rejection cases among the overall description of multiple chambers by the IEC model. The rejected cases were analyzed again by using a non-monotonic trend test and constructing a double Weibull process tub curve strength function, and the 3-stage time interval of the bathtub curve failure is obtained, which is in line with the actual operation data. The Ward clustering method is used for the mean time between failures of 20 chambers, resulting in 4 types of chamber groups with different reliability values (71,52,100,130 days), which is of great significance for studying the reliability of the environmental test chamber and carrying out customized maintenance.

Optimizing the use of open chambers to measure ammonia volatilization in field plots amended with urea

Measuring ammonia (NH3) volatilization from urea-fertilized soils is crucial for evaluation of practices that reduce gaseous nitrogen (N) losses in agriculture. The small area of chambers used for NH3 volatilization measurements compared with the size of field plots may cause significant errors if inadequate sampling strategies are adopted. Our aims were: i) to investigate the effect of using multiple open chambers on the variability in the measurement of NH3 volatilization in urea-amended field plots and ii) to define the critical period of NH3-N losses during which the concentration of sampling effort is capable of reducing uncertainty. The use of only one chamber covering 0.015% of the plot (51.84 m2) generates a value of NH3-N loss within an expected margin of error of 30% around the true mean. To reduce the error margin by half (15%), 3–7 chambers were required with a mean of 5 chambers per plot. Concentrating the sampling efforts in the first two weeks after urea application, which is usually the most critical period of N losses and associated errors, represents an efficient strategy to lessen uncertainty in the measurements of NH3 volatilization. This strategy enhances the power of detection of NH3-N loss abatement in field experiments using chambers.

The effect of the perfluorocarbon emulsion OxycyteTM in an ovine model of severe decompression illness

Background: The treatment of decompression sickness (DCS) with hyperbaric oxygen (HBO2) serves to decrease intravascular bubble size, increase oxygen (O2) delivery to tissue and enhance the elimination of inert gas. Emulsified perfluorocarbons (PFC) combined with breathing O2 have been shown to have similar effects animal models. We studied an ovine model of severe DCS treated with the intravenous PFC OxycyteTM while breathing O2 compared to saline control also breathing O2. Methods: Juvenile male sheep (N=67; weight 24.4+/2.10kg) were compressed to 257 feet of sea water (fsw) in our multiple large-animal chamber where they remained under pressure for 31 minutes. Animals then were decompressed to surface pressure and randomized to receive either Oxycyte at 5mL/kg intravenously (IV) or 5mL/kg saline IV (both receiving 100% O2) 10 minutes after reaching surface pressure. Mortality was recorded at two hours, four hours, and 24 hours after receiving the study drug. Surviving animals underwent perfusion fixation and harvesting of the spinal cord at 24 hours. Spinal cord sections were assessed for volume of lesion area and compared. Results: There was no significant difference in survival at two hours (p=0.2737), four hours (p=0.2101), or 24 hours (p=0.3171). Paralysis at 24 hours was not significantly different. However, spinal cord lesion area was significantly smaller in the Oxycyte group as compared to the saline group, with median spinal cord lesion areas 0.65% vs. 0.94% (p=0.0107). Conclusions: In this ovine model of severe DCS the intravenous PFC Oxycyte did not reduce mortality but did ameliorate spinal cord injury when used after the onset of DCS.

VectorDisk: A Microfluidic Platform Integrating Diagnostic Markers for Evidence-Based Mosquito Control

Effective mosquito monitoring relies on the accurate identification and characterization of the target population. Since this process requires specialist knowledge and equipment that is not widely available, automated field-deployable systems are highly desirable. We present a centrifugal microfluidic cartridge, the VectorDisk, which integrates TaqMan PCR assays in two feasibility studies, aiming to assess multiplexing capability, specificity, and reproducibility in detecting disk-integrated vector-related assays. In the first study, pools of 10 mosquitoes were used as samples. We tested 18 disks with 27 DNA and RNA assays each, using a combination of multiple microfluidic chambers and detection wavelengths (geometric and color multiplexing) to identify mosquito and malaria parasite species as well as insecticide resistance mechanisms. In the second study, purified nucleic acids served as samples to test arboviral and malaria infective mosquito assays. Nine disks were tested with 14 assays each. No false positive results were detected on any of the disks. The coefficient of variation in reproducibility tests was <10%. The modular nature of the platform, the easy adaptation of the primer/probe panels, the cold chain independence, the rapid (2–3 h) analysis, and the assay multiplexing capacity are key features, rendering the VectorDisk a potential candidate for automated vector analysis.

Heterochronic origin of spherical fusulinid foraminifera in the late Paleozoic

AbstractHeterochrony describes acceleration, displacement, and/or retardation of descendants’ development events compared with ancestral states and has often been cited as an important process to bring about morphological novelty. It was coined one-and-a-half centuries ago and has been discussed by both paleobiologists and biologists frequently ever since. Many types of fossil organisms preserve aspects of their development histories in their bones or shells that have been used for heterochrony analyses, with body size being used as a developmental age indicator, despite questions being raised regarding this practice. For organisms whose hard structures consist of multiple chambers, or that contain growth lines, age information suggested by these structures independently can facilitate ontogenetic modeling. In this way, relations among size, shape, and age can be established to document patterns of morphological development.Morphological analysis of pseudoschwagerine fusulinids, a fossil foraminifera group that developed a morphologically novel spherical shell, along with their presumptive triticitid ancestors illustrates this approach to heterochrony analysis. Ontogenetic trajectory comparisons of four major pseudoschwagerine genera, as well as those of triticitids, document relations between their shapes, sizes, and developmental ages. A complex of heterochronic patterns, including peramorphic predisplacement, hypermorphosis, and acceleration, characterize pseudoschwagerine development and appear to be responsible for the novel appearance of large, inflated fusiform and spherical tests in these late Paleozoic benthic foraminifera. The morphometric approach employed in this investigation could be applied widely in the quantitative morphological studies of development histories in a variety of other fossil groups.

Integrated and finger-actuated microfluidic chip for point-of-care testing of multiple pathogens

The integration of gel-based loop-mediated isothermal amplification (gLAMP) and finger-actuated microfluidic chip (μFAchip) was developed for the simultaneous detection of various different types of bacterial pathogens. The developed μFAchip consisted of three PDMS layers attached together by two adhesive tapes. Multiple chambers in the top PDMS layer were used for sample preparation, and the corresponding chambers in the bottom PDMS layer was used for long-term storage of LAMP reagents without DNA templates. The thin PDMS layer in the middle contained cross-shaped cuts as finger-actuated valves for fluid control. To reduce operation steps on the chip, such as pipetting and manipulation of samples, Whatman CloneSaver card was pre-embedded in the top chambers for on-chip DNA extraction and purification. Upon a simple press on the top layer, the finger-actuated valve was opened up, allowing DNA samples on the top layer flow into the bottom reaction chambers for gLAMP reaction. For POCT applications, on-chip LAMP reaction and imaging were conducted on a miniaturized peltier heater and a portable fluorescence imaging system respectively. Under the optimized condition, multiple pathogens were detected simultaneously with high selectivity and sensitivity (as low as 1.6 cells). The developed μFAchip provided a rapid and easy-to-operate platform for gLAMP-based pathogen detection, with the potential for in-field detection, especially in areas with limited resources.

Les caractéristiques des dolmens en Corée et les résultats des recherches récentes

The dolmens are one of the most distinct prehistoric remains in Korea. In total, 51,000 dolmens are distributed in the Korean Peninsula. They have various forms, and they tend to be more densely clustered than those in northeastern China or Kyushu in Japan. Recent excavations and researches bring new results, which are quite different from those previously known. The dolmen with burial precinct were built with multiple burial chambers by piling or laying stones in a given area, and its’ highly likely that the buried people would be relatives. The dolmens in the northern part of the Korean Peninsula have a unique structure: one burial chamber was divided into three to four compartments. This structure is believed to have nothing to do with the types of dolmens. Each compartment could be interpreted as an independent burial because its floor structure was different and human bones came out of each compartment. The traces of cremation have been also confirmed with newly excavated dolmens. In some cases, the cremation was done outside the burial chamber, but sometimes, the cremation was done directly inside the tomb, after having constructed the burial chamber. In this case, burnt earth, charcoal, and burned stones were found in the burial chamber. In general, the Korean dolmens had very poor in grave goods, regardless of region. But recently some luth-type bronze daggers and luth-type bronze spearhead has been excavated from dolmen sites in southern Korea. As same types of bronze artifacts have been found in dolmens in northeastern China, it would suggest the cultural resemblance between two regions. Besides these dolmens, some dolmens were trimmed into tortoise shape, and it drew always a special attention. The process of dolmen transport was restored in experimental ways. The recent excavations and research results of dolmens in Korea would be an important source to better understanding of the dolmen culture in Northeast Asia.

The frequency spectrum and geometry of the Ħal Saflieni Hypogeum appear tuned

The Ħal Saflieni Hypogeum is a unique subterranean Maltese Neolithic sanctuary with a well-documented history of interest in its acoustics (Till, 2017; Debertolis et al., 2015; Reznikoff, 2014; Devereux, 2009; Skeates, 2008; Mifsud and Mifsud 1999; Devereux, 1996; Evans, 1971; Zammit, 1910; Griffiths, 1920). Previous studies have noted its unusual strongly-defined frequency spectrum (Debertolis et al., 2015), but it is unknown if this was coincidental. In this paper, we present evidence that the Hypogeum’s creators shaped the site’s geometry to create or amplify its frequency spectrum, or another property closely correlated with the spectrum. Specifically, we show that the observed spectrum required jointly fine-tuning the dimensions of multiple non-contiguous cave walls across multiple independent chambers, to a degree that seems unlikely to be coincidental. We also note that the peak frequencies are evenly spaced and resemble a whole-tone scale in music, which is also unlikely to be coincidental and suggests the spectrum itself might have held some cultural significance. Taken together, it suggests acoustic or spectral properties may have played a motivational or cultural role for the site's Neolithic creators. This work identifies one of the earliest known examples of a manmade structure with a significant musical element to its interior architecture.

Numerical Simulation and Design Optimization of Baffle Perforations for Better Noise Reduction

An increasing vehicle population always pressurizes to focus on environmental concerns for reduced noise level and harmful emissions. Even though many qualitatively optimized exhaust systems are developed during last two decades, still researchers focus on noise reduction and emission control. Abundant research and development activities are carried out to get a reasonable back pressure drop along with a significant noise reduction in the muffler. The development in computational coding leads to a realistic prediction of flow and acoustic characteristics inside the muffle. Hence the present research work focuses on computational simulation of muffler with single and multi-chambers separated by baffles along with porous pipes. The present work analyses a conventional single baffle muffler configuration and compares the flow behaviour with multi chambers separated by multiple baffle configurations. The shape of the baffle holes is also optimised to get better acoustic performance based on the transmission losses. The flow behaviour and its details are studied inside the muffler to identify the possibility of design improvements. Among the muffler configurations with single and multiple chambers, the overall pressure losses are calculated and compared to get an optimized design with reasonable sound attenuation.

Design and Validation of a Portable Handheld Device to Produce Fine Fibers Using Centrifugal Forces

In the present research project, a novel portable battery-powered handheld device able to produce micron and submicron fibers using centrifugal forces is proposed. The design includes spinnerets with a clamshell configuration with multiple chambers or reservoirs (2, 4, and 8) and different exit orifice diameters (400, 500, 600, and 800 µm). The rotational speed is controlled via an Arduino microcontroller. To validate the design, a series of experiments were conducted and the effect of the orifice diameter, number of chambers, and velocity on the resulting fibers’ diameter and yield was studied. For the experiments, a polymeric solution of Polyvinyl Alcohol (PVA) was prepared. The fiber yield was gravimetrically quantified, and the fiber morphology and diameter were analyzed by means of scanning electron microscopy (SEM). The experimental results showed that spinnerets with an orifice diameter of 500 microns yielded the greatest amount of fibers (0.0777 g). In addition, the number of chambers also affected the amount of fibers produced, and it was determined that the fiber diameter size is dependent on the spinneret speed. Fibers 80 nm in diameter were observed at 6500 rpm.

Air cushion barge platform for offshore wind turbine and its stability at a large range of angle

One of typical bases for floating offshore wind turbines is the barge platform that has merits of simpler structure and lower costs, but disadvantages of significant responses in waves. In order to improve the hydrodynamic performance of the barge platforms, in this paper a novel Air cushion Barge Platform (ACBP) is proposed, into which multiple air chambers are incorporated to mitigate the wave loads and reduce the dynamic motions due to waves. However, the existing analytical method is not suitable for evaluating the righting moment and stability of the ACBP at large angles. To address this issue, a new analytical method is developed, which can be used to quickly calculate its righting moment and evaluate its stability in the whole range of trim angles, including very large one with possible emergence of the platform bottom and so with air leakage from a few chambers before capsized. The newly proposed analytical method is calibrated by the CFD results, and then is employed for investigating the static and dynamic stability of the ACBP for two typical designs.

Experimental study of internal flow structures in cylindrical rotating detonation engines

The internal flow structures of detonation wave were experimentally analyzed in an optically accessible hollow rotating detonation combustor with multiple chamber lengths. The cylindrical RDC has a glass chamber wall, 20 mm in diameter, which allowed us to capture the combustion self-luminescence. A chamber 70 mm in length was first tested using C2H4O2 and H2–O2 as propellants. Images with a strong self-luminescence region near the bottom were obtained, confirming the small extent of the region where most of the heat release occurs as found in our previous research. Based on the visualization experiments, we tested RDCs with shorter chamber walls of 40 and 20 mm. The detonation wave was also observed in the shorter chambers, and its velocity was not affected by the difference in chamber length. Thrust performance was also maintained compared to the longer chamber, and the short cylindrical RDC had the same specific impulse tendency as the cylindrical (hollow) or annular 70-mm chamber RDC. Finally, we calculated the pressure distributions of various chamber lengths, and found they were also consistent with the measured pressure at the bottom and exit. We concluded that the short-chamber cylindrical RDC with equal length and diameter maintained thrust performance similar to the longer annular RDC, further expanding the potential of compact RDCs.