Water Cylinder Research Articles

Scatter estimation and correction using time-of-flight and deconvolution in x-ray medical imaging.

Objective Time-of-flight (TOF) scatter rejection requires a total timing jitter,
including the detector timing jitter and the X-ray source's pulses width, of 50 ps or less
to mitigate most of the effects of scattered photons in radiography and CT imaging.
However, since the total contribution of the source and detector to the timing jitter
can be retrieved during an acquisition with nothing between the source and detector,
it can be demonstrated that this contribution may be partially removed to improve
the image quality.
Approach A scatter correction method using iterative deconvolution of the measured
time point-spread function estimates the number of scattered photons detected in each
pixel. To evaluate the quality of the estimation, GATE was used to simulate the
radiography of a water cylinder with bone inserts, and a head and torso in a system
with total timing jitters from 100 ps up to 500 ps full-width-at-half-maximum.
Main results With a total timing jitter of 200 ps, 89% of the contrast degradation
caused by scattered photons was recovered in a head and torso radiography, compared
to 28% with a simple time threshold method. Corrected images using the estimation
have a percent root-mean square error between 2 and 14% in both phantoms with
timing jitters from 100 to 500 ps which is lower than the error achieved with scatter
rejection alone at 100 ps.
Significance TOF X-ray imaging has the potential to mitigate the effects of the
scattering contribution and offers an alternative to anti-scatter grids that avoids loss
of primary photons. Compare to simple TOF scatter rejection using only a threshold,
the deconvolution estimation approach has lower requirements on both the source and
detector. These requirements are now within reach of state-of-the-art systems.

Fano cavity test and investigation of the response of the Roos chamber irradiated by proton beams in perpendicular magnetic fields up to 1 T

Objective. The aim of this work is to investigate the response of the Roos chamber (type 34001) irradiated by clinical proton beams in magnetic fields. Approach. At first, a Fano test was implemented in Monte Carlo software package GATE version 9.2 (based on Geant4 version 11.0.2) using a cylindrical slab geometry in a magnetic field up to 1 T. In accordance to an experimental setup (Fuchs et al ), the magnetic field correction factors kQB⃗ of the Roos chamber were determined at different energies up to 252 MeV and magnetic field strengths up to 1 T, by separately simulating the ratios of chamber signals MQ/MQB⃗, without and with magnetic field, and the dose-conversion factors Dw,QB⃗/Dw,Q in a small cylinder of water, with and without magnetic field. Additionally, detailed simulations were carried out to understand the observed magnetic field dependence. Main results. The Fano test was passed with deviations smaller than 0.25% between 0 and 1 T. The ratios of the chamber signals show both energy and magnetic field dependence. The maximum deviation of the dose-conversion factors from unity of 0.22% was observed at the lowest investigated proton energy of 97.4 MeV and B⃗ = 1 T. The resulting kQB⃗ factors increase initially with the applied magnetic field and decrease again after reaching a maximum at around 0.5 T; except for the lowest 97.4 MeV beam that show no observable magnetic field dependence. The deviation from unity of the factors is also larger for higher proton energies, where the maximum lies at 1.0035(5), 1.0054(7) and 1.0069(7) for initial energies of E0 = 152, 223.4 and 252 MeV, respectively. Significance. Detailed Monte Carlo studies showed that the observed effect can be mainly attributed to the differences in the transport of electrons produced both outside and inside of the air cavity in the presence of a magnetic field.

Time-of-flight scatter rejection in x-ray radiography.

Objective.Time-of-flight (TOF) scatter rejection allows for identifying and discarding scattered photons without the use of an anti-scatter grid (ASG). Although TOF scatter rejection was initially presented for cone-beam computed tomography, we propose, herein, to extend this approach to x-ray radiography. This work aims to evaluate with simulations if TOF scatter rejection can outperform ASGs for radiography.Approach.GATE was used to simulate the radiography of a head and a torso and a water cylinder with bone inserts in a system with total timing jitters from 0 ps up to 500 ps full-width-at-half-maximum. The transmission factor of TOF scatter rejection for primary and scattered photons was evaluated as if it were a virtual ASG.Main results.With a total timing jitter of 50 ps, TOF scatter rejection can reach a selectivity of 4.93 with a primary photons transmission of 99%. Reducing the timing jitter close to 0 ps increases the selectivity up to 15.85 for a head and torso radiography, outperforming typical ASGs which usually have a selectivity from 2.5 to 10 with a primary photons transmission from 50% to 70%.Significance.This suggests that TOF scatter rejection may be suitable to replace ASGs in applications requiring lower radiation exposure if sufficiently low timing jitter is achieved.

Direct Measurements of Vortex-Induced Vibrations on a Horizontal Flexible Cylinder in Water

Abstract This work presents experimental results on vortex-induced vibration (VIV) of a horizontal cylinder with 2.69 m in length, 21 mm in diameter, and a mass ratio equal to 3.9. The experiments were carried out in a towing tank, where the flexible cylinder was towed under constant current profiles. Twenty reduced velocities were tested in a range of 1.75 < Vr < 15.79, corresponding to Reynolds numbers from 1000 to 10,000. The displacements were measured directly through a submerged optical system that simultaneously acquired the in-line and cross-flow movements of 18 reflective targets along the length. The extensive monitored section of the model enabled the application of a modal decomposition technique, which is a methodology that is still relatively unexplored through direct measurements. A comprehensive analysis was applied and the VIV responses related to amplitudes, frequencies, phase angles, and trajectories are shown and discussed in depth. The overall dynamics exhibits a multimodal response behavior, and the modal decomposition procedure has conclusively confirmed that the total amplitude comprises several modes vibrating at the dominant mode frequency. Root mean square values of response amplitude were up to 0.77D and 0.23D in the cross-flow and in-line directions, respectively. The cross-flow synchronization had a significant impact on the in-line excitation modes, and the trajectories showed coherence between motions.

Peak loads vs. cold showers: the impact of existing and emerging hot water controllers on load management

ABSTRACT Electric Hot Water Cylinders (HWCs) offer considerable Demand Side Management in Aotearoa New Zealand, which can provide load management and increase integration of renewable electricity. In this work, scenario analyses are conducted to simulate the impact on Low Voltage transformer load and demand fulfilment of four HWC controller types: setpoint (the default in Aotearoa New Zealand), ripple, smart-power, and smart-thermostat. All controllers reduce peak electricity demand by 14-34% from setpoint, where 34% is the maximum possible reduction with hot water control. Unmet demand, which indicates insufficient hot water and can lead to negative outcomes such as cold showers, is increased by 120% and 12-69% by ripple and smart-power control, respectively, and decreased by 7-31% by smart-thermostat control. Average thermal losses are 2.25 kWh/day for the setpoint controller, and between 2.20-2.76 kWh/day for other controllers. Smart-power controllers demonstrate demand deferral, shifting peak electricity loads to shoulder loads, while smart-thermostat controllers demonstrate demand deferral and valley filling, shifting peak loads to times of lowest demand and smoothing load distribution. Overall, smart controllers improve load management performance with little-to-no increase in unmet demand or thermal losses. Thus, smart controllers are a viable option for Demand Side Management in Aotearoa New Zealand. Abbreviations and Nomenclature: DHW: Domestic Hot Water; DLC: Dynamic Load Control; DSM: Demand Side Management; EV: Electric Vehicle; GHG: Green House Gas; HV: High Voltage; HWC: Hot Water Cylinder; LDC: Load Duration Curve; LV: Low Voltage; MV: Medium Voltage; NZD: New Zealand Dollar; PV: PhotoVoltaic; TOU: Time Of Use; UD: Unmet Demand; WTP: Willingness To Pay; A: WTP function coefficient; B: WTP function coefficient; Cp: specific heat of water [J/kg/K]; Ctrans: cost imposed by the transformer; HWsuff: ratio of hot water sufficiency; Kloss,h: thermal losses for cylinder h [W/K]; Kmix: thermostatic mixing valve factor; m: WTP function coefficient; Ptotal: transformer power demand [W]; Pcap: transformer capacity [W]; Ph: Household power demand [W].; PHWC: heater element power [W]; Pop: Transformer limit for Type3 controller [W]; QDHW: heat loss from DHW use [W]; Qloss: heat loss from standing losses [W]; th: time horizon [s]; Tamb: ambient temperature [K]; THWC: temperature of the HWC [K]; Tin: water inlet temperature [K]; Tmin: minimum temperature before fulfilment failure; Tout: water outlet temperature [K].; Tset: temperature setpoint of the HWC controller [K]; V ˙ : flow rate of hot water from the HWC [L/s]; Vavail: available DHW in the HWC [L]; VDHW: volume of hot water draw [L]; VDHW,expected: expected time weighted demand; VDHW,expected,max: maximum expected DHW demand; VHWC: volume of the HWC [L]; wf: time weighting function; ρ: density of water [kg/m3].

Evaluation of radiation dose caused by bremsstrahlung photons generated by high-energy beta rays using the PHITS and GEANT4 simulation codes

ABSTRACT High-energy beta-ray sources generate bremsstrahlung photons in the building materials, generated by the radioactive nuclides inside the nuclear reactor buildings emitted by the Fukushima Daiichi nuclear reactor accident. Therefore, evaluating the bremsstrahlung dose subjected to the workers in the building is crucial for radiation protection. The precision for assessing the bremsstrahlung dose was investigated by comparing the Particle and Heavy Ion Transport code System (PHITS) and the GEometry ANd Tracking (GEANT4) simulation code results. Behind various shielding plates (lead, copper, aluminum, glass, and polyethylene with multiple thicknesses), the water cylinder was set to obtain the absorbed dose and the deposited energy spectrum by the bremsstrahlung photons. In comparing the deposited energy spectrum, the spectral shapes have consistent trends. Below several tens of keV, a peak is observed in the PHITS spectrum for lead. While comparing the absorbed dose, most of the results from both codes correlate within an ~10% difference for 2.280 MeV beta-ray sources and an ~20% difference for 0.5459 MeV beta-ray sources, except for ~30% for 20 mm thick lead. Although some differences occurred, the evaluation results of both codes correlated well with the above precision.

On the Added Modal Coefficients of a Rotating Submerged Cylinder Induced by a Whirling Motion—Part 2: Numerical Investigation

Part 2 of this work presents a numerical methodology, validated using the experimental results presented in Part 1, to calculate the added modal coefficients of a submerged cylinder in water both when it oscillates and when it rotates with a whirling motion. The numerical methodology is based on computational fluid dynamic simulations that obtain the added modal forces on the cylinder when it is forced to vibrate with mode shapes calculated using acoustic-structural modal analysis. Then, these forces are processed with a curve-fitting algorithm to extract all the coefficients. Most numerical coefficients presented a close agreement with the corresponding experimental ones, although the added modal damping was overestimated. In general, the added modal mass was found to be independent of both the rotating speed and the whirling frequency except for low whirling frequencies when it increased. The added modal damping was found to depend on both parameters, and the rest of the coefficients were independent of the whirling frequency and only depended on the rotating speed. As a conclusion, this numerical approach has permitted the study of particular conditions that could not be experimentally tested and thus broadened the knowledge of the behavior of the added modal coefficients of rotating submerged cylinders.

Base Bleed Flow Control Tool for Circular Cylinders with three Side-By-Side Arrangements in Shallow Water

In this study, Particulate Image Velocimetry (PIV) was utilized to determine the flow characteristics of three side-by-side circular cylinders with a base bleed. The height of the water was set as hW=20 mm which has characteristics of shallow water and flow images were captured from an elevation of hL/hW= 0.5 (mid-plane of water height). The freestream velocity of water and circular cylinder diameters were chosen as U∞=0.125 m/sec and D=40 mm, respectively which are the corresponding Reynolds number of ReD=5000. Three different gap/diameter ratios between the cylinders were tested as G/D=1.0, 1.25, and 1.5 throughout the experiments. As a passive flow control technique, base bleed slots located through the cylinders were used with the dimensionless width ratio of B/D= 0.05 to 0.25 with 0.05 increment. As a result of the study, the base bleed was found out an effective way to control unsteady wake. Besides, whereas the increasing height of VSP results in further decrement turbulence statistics, Increasing the width of base bleed leads to a reduction of maximum Reynolds shear stress concentration. Nevertheless, jet deflection flow cannot be avoided for the G/D=1.25 while, flow deflection is avoided with all base bleed case the gap ratio increases to G/D=1.5. The wake size of each cylinder is almost the same for G/D=1.5.

A MONTE CARLO CALIBRATION APPROACH FOR A DUAL-ENERGY CT SYSTEM

This work shows the effectiveness of Monte Carlo methods for calibrating a dual-energy CT (DECT) system on a heterogeneous phantom for radiotherapy. The reference phantom comprising 20 inserts of different materials and densities representing human tissues inserted in a plastic water cylinder has been considered. The reliability of the model, built with the Penelope code, has been verified by comparing the results of the simulations at 80[Formula: see text]kVp and 140[Formula: see text]kVp with the experimental data acquired from the CT scans and dosimetry measurements. The effective atomic number from the various materials is also considered a control parameter. Tests for calibration and dose calculation are also based on a homogeneous phantom in PMMA and measurements in air with an ionization chamber. The Monte Carlo simulations coupled with dose evaluations allowed the calibration of the dose deposition effects on the considered tissue models.

Modeling Impact Load on a Vertical Cylinder in Dam-Break Flows

A three-dimensional dam-break flow interacting with a vertical circular and square cylinder is studied in this paper using computational fluid dynamics simulations based on OpenFOAM. This resembles closely a tsunami wave and greenwater flow acting on coastal or on-deck structures, which are of relevance and importance to coastal protections and offshore operations, respectively. The numerical model is verified by comparing with published experimental measurements and is extended to investigate the effects of the structural geometry and the impacting angle β (i.e., the angle between the water front and cylinders) on the total impact load and the surrounding flow field. It is found that the impact event experiences two distinct stages characterized by a constant flow velocity and a negative flow acceleration, respectively. In addition, the total force on a square cylinder is nearly twice that of a circular cylinder although the impacting area is the same. The longitudinal and transverse forces are found to decrease and increase with the impacting angle, respectively. A close interrogation of the surrounding flow field via flow visualization suggests that the way the flow deflected from the cylinder surfaces plays an important role in determining the pressure field and thus the total force behaviors.

Reduction of wave load on monopile-supported offshore wind turbine by a gear-type plate

This study investigates the wave diffraction problem of a vertical cylinder with a gear-type plate by using the linear wave theory and the method of eigenfunction expansion. The present model is demonstrated to be accurate, through a comparison with the numerical results of the boundary element method. The horizontal wave force acting on the cylinder can be reduced considerably by the gear-type plate. Meanwhile, the variation in bending moment at the bottom of the cylinder depends on the wave conditions and geometry parameters. A low value of the ratio between water depth and cylinder radius (d/r0) can result in an increase in the bending moment on the cylinder, rather than a decrease, due to the additional loads exerted by the gear-type plate. The bending moment on the cylinder can be reduced significantly by the gear-type plate as d/r0 increases. Within d/r0∈[4,10] of the present monopile-supported wind turbines, the wave loads on the monopile foundation can be reduced significantly by the proposed gear-type plate. Compared with a ring-type plate, a gear-type plate exhibits superior reduction effects over an equal plate area. The loads on the structures are insensitive to the wave exposure angle when the teeth number increases beyond three.

Assessing the energy storage potential of electric hot water cylinders with stochastic model-based control

ABSTRACT As electric hot water cylinders (HWCs) have a large capacity for thermal storage, they are well-suited for Demand Side Management (DSM). This paper compares different methods of HWC temperature control and presents a methodology to assess the amount of thermal storage available in HWCs for demand side management based on use behaviour in different household types. Simple stochastic methods for domestic hot water (DHW) demand prediction were employed to design a smart controller that produced lower rates of unmet DHW demand and higher available storage than setpoint and ripple controllers. The average storage available for DSM from the use of this smart controller is predicted to be between 3.63 and 7.20 kWh per household. These results indicate the use of HWCs for thermal storage is a low-cost viable option for peak-shaving of power system load and could decrease power system greenhouse gas (GHG) emissions in countries such as Aotearoa New Zealand, where GHG-emitting electricity generation is primarily used to meet peak loads.

A likelihood-based particle imaging filter using prior information.

Particle imaging can increase precision in proton and ion therapy. Interactions with nuclei in the imaged object increase image noise and reduce image quality, especially for multinucleon ions that can fragment, such as helium. This work proposes a particle imaging filter, referred to as the Prior Filter, based on using prior information in the form of an estimated relative stopping power (RSP) map and the principles of electromagnetic interaction, to identify particles that have undergone nuclear interaction. The particles identified as having undergone nuclear interactions are then excluded from the image reconstruction, reducing the imagenoise. The Prior Filter uses Fermi-Eyges scattering and Tschalär straggling theories to determine the likelihood that a particle only interacts electromagnetically. A threshold is then set to reject those particles with a low likelihood. The filter was evaluated and compared with a filter that estimates this likelihood based on the measured distribution of energy and scattering angle within pixels, commonly implemented as the 3σ filter. Reconstructed radiographs from simulated data of a 20-cm water cylinder and an anthropomorphic chest phantom were generated with both protons and helium ions to assess the effect of the filters on noise reduction. The simulation also allowed assessment of secondary particle removal through the particle histories. Experimental data were acquired of the Catphan CTP 404 Sensitometry phantom using the U.S. proton CT (pCT) collaboration prototype scanner. The proton and helium images were filtered with both the prior filtering method and a state-of-the-art method including an implementation of the 3σ filter. For both cases, a dE-E telescope filter, designed for this type of detector, was alsoapplied. The proton radiographs showed a small reduction in noise (1mm of water-equivalent thickness [WET]) but a larger reduction in helium radiographs (up to 5-6mm of WET) due to better secondary filtering. The proton and helium CT images reflected this, with similar noise at the center of the phantom (0.02 RSP) for the proton images and an RSP noise of 0.03 for the proposed filter and 0.06 for the 3σ filter in the helium images. Images reconstructed from data with a dose reduction, up to a factor of 9, maintained a lower noise level using the Prior Filter over the state-of-the-art filteringmethod. The proposed filter results in images with equal or reduced noise compared to those that have undergone a filtering method typical of current particle imaging studies. This work also demonstrates that the proposed filter maintains better performance against the state of the art with up to a nine-fold dose reduction.

Flow regime transitions for Aiding flow around a heated cylinder: A numerical and experimental investigation

Experiments and numerical simulations were performed to examine the interplay between buoyancy and momentum effects for mixed convection flow around a 13.4 mm diameter cylinder in water. PIV and LIF measurements were made to obtain experimental velocity and temperatures over a Ri range from 0 to 9. LES models were validated against the measured experimental conditions and then used to numerically study the parametric behaviour over a wider range of conditions. The CFD model was found to perform well, with a small tendency to over predict temperature and velocity measurements for higher buoyancy conditions, Ri > 1.9. Using the experimental LIF results, three flow regimes around the cylinder were identified, grouped, and made into a flow regime map. From this, two sets of transition criteria were developed and proposed to predict the collapse of the recirculation zone and the total suppression of vortex formation. This was done via observations from the experimental data and additional CFD simulations to examine the separate effects of fluid properties and incident turbulence levels, both of which were shown to influence vortex suppression significantly. The criteria proposed was found to accurately capture the visually observed flow regimes experimentally in water.

Acoustic metafluids of shear modulus enabling surface waves

Metafluids, the version of metamaterials with fluid background, are generally characterized by two parameters: the effective mass density and bulk modulus. However, we recently theoretically demonstrated that a metafluid, with built-in quadrupolar resonances, can counterintuitively accommodate a third parameter, the effective shearlike modulus. In this letter, we go further to experimentally implement this metafluid, realized as a square lattice array of hollow steel cylinders in water. The effective parameters are extracted by matching the measured dispersion curves with the effective medium theory. By virtue of the emergent parameter, the metafluid can intrinsically support surface waves at the interface with water, which updates the knowledge that surface waves cannot exist at the interface of two fluids. Our work has potential in expanding the applications of metafluids.

Instability and Atomization of Liquid Cylinders after Shock Wave’s Impacting

This paper describes an experimental study on the instability and atomization of liquid cylinders after the impact of shock waves. Single row water column, in-line double rows water columns and alongside triple rows water columns were evaluated in a horizontal shock tube. The diameter of water column and the Mach number in the experiments were 2.0–4.14 mm and 1.10–1.25, respectively. The global instability along the axial direction of water cylinders was focused. Using a high-speed camera, the developments of spike height, bubble depth and turbulent mixing zone, width were measured. Some comparison was also made between the present experimental results and the existing theoretical model.

An inverse-problem approach to simulating smart control of domestic electric hot water cylinders using electricity demand time-series data.

Smart control of domestic electric hot water cylinders could be used as a relatively inexpensive option to help bridge supply–demand mismatches in highly-renewable electricity grids in many countries. Evaluation of options for the smart control of these cylinders is made difficult by the lack of domestic hot water flow time-series data. In contrast, hot water cylinder electricity demand time-series data, either directly measured or imputed from whole house data, is often much more readily available. In this paper, we propose an inverse-problem approach that uses a physical model of a hot water cylinder to determine hot water flow information from electricity demand data. Once hot water flow information has been determined, it is then possible to simulate smart control of the hot water cylinder element such that it does not interfere with the provision of hot water. We illustrate this approach by using a simple physical model of a hot water cylinder to simulate the hot water flow of 19 houses with electric hot water cylinders from measured time-series electricity data. A smart control case study is then explored where these houses are part of a solar PV microgrid and the cylinder elements are controlled so as to reduce the battery storage needed by the microgrid to reach a certain level of self sufficiency.

Impact of CT tube-voltage and bone density on the quantitative assessment of tracer uptake in Tc-99m bone SPECT/CT: A phantom study

PurposeTo evaluate the effect of computed tomography (CT) tube voltage and CT density for CT-based attenuation correction (CTAC) on quantification of tracer uptake in single photon emission computed tomography (SPECT)/CT. MethodsA cylindrical phantom contained 7 cylinders with diameter of 30 mm. The central cylinder and background part were filled with 17 kBq/ml of 99mTc-pertechnetate solution. Of the remaining 6 cylinders, one cylinder was filled with water and 5 cylinders were filled with each own different concentration of K2HPO4 solution (120, 275, 450, 666, and 960 mg/cm3) to simulate different bone densities. The 6 cylinders also contained 99mTc-pertechnetate solution with the same radioactivity concentration (207 kBq/ml). CT scans were performed with 4 different tube voltages of 80, 100, 120, and 140 kVp for CTAC. The radioactivity concentration in the 6 cylinders were measured on the SPECT images processed with 4 different attenuation coefficient maps derived from each tube voltage of CT images. ResultsCompared with the water cylinder without K2HPO4 solution, the measured radioactivity of the highest density cylinder (K2HPO4 solution concentration: 960 mg/cm3) was found to be overestimated by 3.3 % and 4.3 %, respectively, when the tube voltage was 120 kVp and 140 kVp (p = 0.022). The use of low-tube voltage, such as 80 kVp, has improved the quantitative accuracy of bone SPECT/CT. ConclusionsSPECT quantitative evaluation of tracers in high-density objects tends to overestimate as tube voltage for CTAC increases. However, the overestimation in quantitative SPECT/CT evaluation in simulated bone area is less than 5% at most.

Projection Deconvolution for Proton CT Using the Spatially Variant Path Uncertainty

Proton computed tomography (pCT) suffers from a lower spatial resolution compared to X-ray CT due to the stochastic nonlinear proton paths. The most likely path (MLP) formalism provides an estimate for the proton path as well as the uncertainty around this estimate. Using the MLP estimate for the image reconstruction instead of straight integration lines has been shown to improve the spatial resolution of pCT images. In this work, the aim is to further increase the spatial resolution by also including the path uncertainty in the reconstruction algorithm. We proposed a projection-based deconvolution method, applied within the framework of a direct reconstruction algorithm based on distance-driven binning. We used an MLP formalism accounting for tracker resolution in addition to multiple Coulomb scattering (MCS). We investigated deconvolution artifacts and proposed a method to mitigate them via spatial regularization. Our method was tested on Monte Carlo simulated data, using a water cylinder with aluminium inserts and two slices of an anthropomorphic phantom. Our results showed an improvement of spatial resolution in all cases (up to 29% or 60% for the cylindrical phantom, depending on whether deconvolution artifacts were corrected for or not). Overshoot artifacts were observed in the case of the cylindrical phantom but were less prominent in the case of the anthropomorphic phantom. In conclusion, we have shown that including the path uncertainty in the reconstruction can notably improve the spatial resolution.

On analytical solutions for transient water waves radiated by cylinders

Analytical solutions for transient water waves radiated by a circular cylinder in deep water are studied in this paper. Within the framework of the potential flow and linear water wave theory, time-domain solutions are analytically derived based on decomposition of the velocity potential consisting of an instantaneous term and a memory term. These two terms are solved by satisfying the governing equations and initial boundary conditions. Transient concentric water waves are further studied and evaluated for a pulsating circular cylinder which expands and contracts radially. Results are compared with those from other numerical models with a good agreement in terms of wave elevation on the free surface. Analytical solutions obtained in this work can be considered as a benchmark in time-domain analysis for linear hydrodynamic problems, and are of help to the theory and application of wavemakers and transient water waves.