Radiation Hydrodynamics Research Articles

Reconstruction of the deterministic turbulent boundary layer for the study of aerofoil self-noise mechanisms

In the experimental aeroacoustics, it is always a challenge to study the far-field radiation and near field hydrodynamics simultaneously, and be able to firmly establish the causality between them. The main objective of this paper is to present an experimental technique that can exploit the deterministic turbulent boundary layer generated under a base flow of either mildly separated or laminar boundary layer to either disrupt an existing acoustic scattering mechanism, or reconstruct a new acoustic scattering scenario to enable the ensemble-averaging and wavelet analysis to study the aerofoil trailing edge noise source mechanisms in the spatial, temporal and frequency domains. One of the main attractions of this technique is that the experimental tool does not need to be extremely high fidelity as a priori in order to fully capture the pseudo time-resolved boundary layer instability or turbulent structures. In one of the case studies presented here, roll-up vortices of the order of ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} kHz can be captured accurately by a 15-Hz PIV. A single hot-wire probe is also demonstrated to be capable of reconstructing the turbulent/coherent structures in a spatio−temporal domain. The proposed experimental technique can be extended to other self-noise scenarios when the aerofoil trailing edge is subjected to different flow control treatments, such as the porous structure, surface texture, or finlet, whose mechanisms are largely not understood very well at present.Graphical abstract

Time-dependent subsonic ablation pressure scalings for soft X-ray heated low- and intermediate-Z materials at drive temperatures of up to 400 eV

The soft X-ray driven subsonic ablation of five different materials with atomic numbers ranging from 3.5 to 22 is investigated for radiation drive temperatures of up to 400eV. Simulations were performed using the one-dimensional radiation hydrodynamics simulation code HYADES. For each material, ablation pressure scaling-laws are determined as a function of drive radiation-temperature and time, assuming that the irradiation lasts for a period of a few nanoseconds and that the drive temperature remains constant during this period. For all the materials, the maximum drive-temperature for subsonic operation is identified. As expected, lower-Z materials demonstrate a stronger scaling of ablation pressure with radiation temperature and a more gradual fall off with time. However, the lowest-Z materials transition to trans- and super-sonic ablation at temperatures of only a few hundred eV.

Thermal Instability in Radiation Hydrodynamics: Instability Mechanisms, Position-dependent S-curves, and Attenuation Curves

Local thermal instability can plausibly explain the formation of multiphase gas in many different astrophysical environments, but the theory of local TI is only well-understood in the optically thin limit of the equations of radiation hydrodynamics (RHD). Here, we lay groundwork for transitioning from this limit to a full RHD treatment assuming a gray opacity formalism. We consider a situation where the gas becomes thermally unstable due to the hardening of the radiation field when the main radiative processes are free–free cooling and Compton heating. We identify two ways in which this can happen: (i) when the Compton temperature increases with time, through a rise in either the intensity or energy of a hard X-ray component; and (ii) when attenuation reduces the flux of the thermal component such that the Compton temperature increases with depth through the slab. Both ways likely occur in the broad-line region of active galactic nuclei where columns of gas can be ionization-bounded. In such instances where attenuation is significant, thermal equilibrium solution curves become position-dependent and it no longer suffices to assess the stability of an irradiated column of gas at all depths using a single equilibrium curve. We demonstrate how to analyze a new equilibrium curve—the attenuation curve—for this purpose, and we show that, by Field’s instability criterion, a negative slope along this curve indicates that constant-density slabs are thermally unstable whenever the gas temperature increases with depth.

Investigating laser ablated plume dynamics of carbon and aluminum targets

Recently acquired high-resolution images of nanosecond laser ablation plumes suggest a strong correlation between the internal plume structure and the type of material being ablated. However, the details of this relation are currently not well understood. In this work, we attempt to explore this correlation using a 2D radiation hydrodynamics model to study the dependence of internal plume structure formation on the ablation material. Spatio-temporal emission maps and plume expansion velocities from experimental measurements are compared with the model predictions, including synthetic emission maps. The shape and expansion rate of an outer air plume region are found to be in good agreement for both carbon and aluminum, as are the inner material plume dynamics for carbon ablation. The largest disagreement is observed in the case of a polished aluminum target, where the chaotic inner plume features seen in the experimental images are not observed in the model. The possible physical mechanisms responsible for this discrepancy are discussed. This effort constitutes a continued development toward a predictive model of ablation plume dynamics and chemistry for various materials in extreme environments.

Ice Age: Chemodynamical Modeling of Cha-MMS1 to Predict New Solid-phase Species for Detection with JWST

Chemical models and experiments indicate that interstellar dust grains and their ice mantles play an important role in the production of complex organic molecules (COMs). To date, the most complex solid-phase molecule detected with certainty in the interstellar medium is methanol, but the James Webb Space Telescope (JWST) may be able to identify still larger organic species. In this study, we use a coupled chemodynamical model to predict new candidate species for JWST detection toward the young star-forming core Cha-MMS1, combining the gas–grain chemical kinetic code MAGICKAL with a 1D radiative hydrodynamics simulation using Athena++. With this model, the relative abundances of the main ice constituents with respect to water toward the core center match well with typical observational values, providing a firm basis to explore the ice chemistry. Six oxygen-bearing COMs (ethanol, dimethyl ether, acetaldehyde, methyl formate, methoxy methanol, and acetic acid), as well as formic acid, show abundances as high as, or exceeding, 0.01% with respect to water ice. Based on the modeled ice composition, the infrared spectrum is synthesized to diagnose the detectability of the new ice species. The contribution of COMs to IR absorption bands is minor compared to the main ice constituents, and the identification of COM ice toward the core center of Cha-MMS1 with the JWST NIRCAM/Wide Field Slitless Spectroscopy (2.4–5.0 μm) may be unlikely. However, MIRI observations (5–28 μm) toward COM-rich environments where solid-phase COM abundances exceed 1% with respect to the column density of water ice might reveal the distinctive ice features of COMs.

Reionization time of the Local Group and Local-Group-like halo pairs

ABSTRACT Patchy cosmic reionization resulted in the ionizing UV background asynchronous rise across the Universe. The latter might have left imprints visible in present-day observations. Several numerical simulation-based studies show correlations between the reionization time and overdensities and object masses today. To remove the mass from the study, as it may not be the sole important parameter, this paper focuses solely on the properties of paired haloes within the same mass range as the Milky Way. For this purpose, it uses CoDaII, a fully coupled radiation hydrodynamics reionization simulation of the local Universe. This simulation holds a halo pair representing the Local Group, in addition to other pairs, sharing similar mass, mass ratio, distance separation, and isolation criteria but in other environments, alongside isolated haloes within the same mass range. Investigations of the paired halo reionization histories reveal a wide diversity although always inside-out, given our reionization model. Within this model, haloes in a close pair tend to be reionized at the same time but being in a pair does not bring to an earlier time their mean reionization. The only significant trend is found between the total energy at z = 0 of the pairs and their mean reionization time: Pairs with the smallest total energy (bound) are reionized up to 50 Myr earlier than others (unbound). Above all, this study reveals the variety of reionization histories undergone by halo pairs similar to the Local Group, that of the Local Group being far from an average one. In our model, its reionization time is ∼625 Myr against 660 ± 4 Myr (z ∼ 8.25 against 7.87 ± 0.02) on average.

Hydrodynamic modelling of pulsation period decrease in the Mira-type variable T UMi

ABSTRACT Pulsation period decrease during the initial stage of the thermal pulse in the helium-burning shell of the Mira-type variable T UMi is investigated with numerical methods of stellar evolution and radiation hydrodynamics. To this end, a grid of evolutionary tracks was calculated for stars with masses on the main sequence $1\, \mathrm{M}_{\odot }\le M_\mathrm{ZAMS}\le 2.2\, \mathrm{M}_{\odot }$ and metallicity Z = 0.01. Selected models of AGB evolutionary sequences were used for determination of the initial conditions and the time-dependent inner boundary conditions for the equations of hydrodynamics describing evolutionary changes in the radially pulsating star. The onset of period decrease during the initial stage of the thermal pulse is shown to nearly coincide with the peak helium-burning luminosity. The most rapid decrease of the period occurs during the first three decades. The pulsation period decreases due to both contraction of the star and mode switching from the fundamental mode to the first overtone. The time-scale of mode switching is of the order of a few dozen pulsation cycles. The present-day model of the Mira-type variable T UMi is the first-overtone pulsator with small-amplitude semiregular oscillations. Theoretical estimates of the pulsation period at the onset of period decrease and the rate of period change three decades later are shown to agree with available observational data on T UMi for AGB stars with masses $1.04\, \mathrm{M}_{\odot }\le M\le 1.48\, \mathrm{M}_{\odot }$.

Quantitative spatiotemporal density evolution of aluminum heated purely by monochromatic electrons

A spatially resolved air-wedge shearing interferometer and shadowgraph diagnostic provides measurements of electron density with a resolution of ∼40 μm. A ∼100-ns-long, monoenergetic electron bunch at 19.8 MeV and a current of 1.4 kA (8.5×1014 e−) heats 100-μm-thick aluminum (Al) foils in a 1-mm-spot to Te∼1 eV. A 5-ns-long, ∼60 mJ, frequency doubled Nd:YAG laser probes the dense Al plasma. Electron densities up to 1020cm−3 are resolved; the maximum resolvable density is limited by opacity, transmission, and spatial fringe density achievable with the detector. This diagnostic provides measurements of the total phase shift, transmission, and electron density. Several measurements at different time slices provide the ability to determine the velocity of the leading edge of the shadowgraph and compare it to the motion of different density shells. These measurements are also compared to radiation hydrodynamics simulations. A rough quantitative agreement is shown between the hydro simulations and the measurements; there are differences in the exact density distributions.

Supersonic–subsonic transition region in radiative heat flow via self-similar solutions

We study the radiative hydrodynamics flow of radiation-driven heat waves in hot dense plasmas, using approximate self-similar solutions. Specifically, we have focused on the intermediate regime between the pure radiative supersonic flow and the pure subsonic regime. These two regimes were investigated using both exact self-similar solutions and numerical simulations; however, most of the study used numerical simulations, mainly because the radiative heat wave and the shock regions are not self-similar altogether. In a milestone work [Garnier et al., “Self-similar solutions for a nonlinear radiation diffusion equation,” Phys. Plasmas 13, 092703 (2006)], it was found that for a specific power law dependency temperature profile, a unique exact self-similar solution exists that is valid for all physical regimes. In this work, we approximate Garnier's exact solution for a general power-law temperature-dependency, using simple analytical considerations. This approximate solution yields a good agreement compared to numerical simulations for the different thermodynamic profiles within the expected range of validity. In addition, we offer an approximate solution for the energies absorbed in the matter, again, for a general power-law temperature profile. Our approximate self-similar solution for the energy yields very good results compared to exact numerical simulations for both gold and Ta2O5. We also set a comparison of our self-similar solutions with the results of an experiment for radiation temperature measurement in a Hohlraum in low-density foams that is addressed directly to the intermediate regime, yielding a good agreement and similar trends. The different models as well as the numerical simulations are powerful tools to analyze the supersonic–subsonic transition region.

Mg ii in the JWST era: a probe of Lyman continuum escape?

ABSTRACT Limited constraints on the evolution of the Lyman Continuum (LyC) escape fraction represent one of the primary uncertainties in the theoretical determination of the reionization history. Due to the intervening intergalactic medium, the possibility of observing LyC photons directly in the epoch of reionization is highly unlikely. For this reason, multiple indirect probes of LyC escape have been identified, some of which are used to identify low-redshift LyC leakers (e.g. O32), while others are primarily useful at z > 6 (e.g. [O iii]/[C iii] far-infrared emission). The flux ratio of the resonant Mg ii doublet emission at 2796$\mathring{\rm A}$ and 2803$\mathring{\rm A}$ as well as the Mg ii optical depth have recently been proposed as ideal diagnostics of LyC leakage that can be employed at z > 6 with JWST. Using state-of-the-art cosmological radiation hydrodynamics simulations post-processed with CLOUDY and resonant-line radiative transfer, we test whether Mg ii is indeed a useful probe of LyC leakage. Our simulations indicate that the majority of bright, star-forming galaxies with high LyC escape fractions are expected to be Mg ii emitters rather than absorbers at z = 6. However, we find that the Mg ii doublet flux ratio is a more sensitive indicator of dust rather than neutral hydrogen, limiting its use as a LyC leakage indicator to only galaxies in the optically thin regime. Given its resonant nature, we show that Mg ii will be an exciting probe of the complex kinematics in high-redshift galaxies in upcoming JWST observations.

The impact of ultraviolet heating and cooling on the dynamics and observability of lava planet atmospheres

ABSTRACT Lava planets have non-global, condensible atmospheres similar to icy bodies within the Solar system. Because they depend on interior dynamics, studying the atmospheres of lava planets can lead to understanding unique geological processes driven by their extreme environment. Models of lava planet atmospheres have thus far focused on either radiative transfer or hydrodynamics. In this study, we couple the two processes by introducing ultraviolet (UV) and infrared (IR) radiation to a turbulent boundary layer model. We also test the effect of different vertical temperature profiles on atmospheric dynamics. Results from the model show that UV radiation affects the atmosphere much more than IR. UV heating and cooling work together to produce a horizontally isothermal atmosphere away from the substellar point regardless of the vertical temperature profile. We also find that stronger temperature inversions induce stronger winds and hence cool the atmosphere. Our simulated transmission spectra of the bound atmosphere show a strong SiO feature in the UV that would be challenging to observe in the planet’s transit spectrum due to the precision required. Our simulated emission spectra are more promising, with significant SiO spectral features at 4.5 and 9 $\mu$m that can be observed with the James Webb Space Telescope. Different vertical temperature profiles produce discernible dayside emission spectra, but not in the way one would expect.

Modelling star cluster formation: Mergers

Abstract Star cluster formation in giant molecular clouds involves the local collapse of the cloud into small gas-rich subclusters, which can then subsequently collide and merge to build up the final star cluster(s). In this paper, we simulate collisions between these subclusters, using coupled smooth particle hydrodynamics for the gas and N-body dynamics for the stars. We are guided by previous radiation hydrodynamics simulations of molecular cloud collapse which provide the global properties of the colliding clusters, such as their stellar and gas masses, and their initial positions and velocities. The subclusters in the original simulation were treated as sink particles which immediately merged into a single entity after the collision. We show that the more detailed treatment provides a more complex picture. At collisional velocities above ≈ 10 km/s, the stellar components of the cluster do not form a monolithic cluster within 3 Myr, although the gas may do so. At lower velocities, the clusters do eventually merge but over timescales that may be longer than the time for a subsequent collision. The structure of the resultant cluster is not well-fit by any standard density distribution, and the clusters are not in equilibrium but continue to expand over our simulation time. We conclude that the simple sink particle treatment of subcluster mergers in large-scale giant molecular cloud simulations provides an upper limit on the final cluster properties.

Formation of singularities of solutions to a 1D compressible radiation hydrodynamics model

In this paper we are concerned with a 1D compressible radiation hydrodynamics model, which is described by a Navier–Stokes-elliptic coupled system of equations without viscosity. We prove that the smooth solutions to this model would blow up in finite time provided the first derivatives of the initial data are less than some negative constant although the initial data themselves are small. Moreover, it is shown that the singularity is indeed a shock singularity.

Numerical simulation of the effect of laser wavelength on nanosecond laser ablation and plasma characteristic

Based on the heat conduction equation, hydrodynamics equations, and radiation transport equation, a two-dimensional axisymmetric radiation hydrodynamics model is developed. The charge state distribution and energy level population in the plasma are solved by the collisional-radiative model using screened hydrogenic levels. The model is used to study the effect of excitation laser wavelength at 1064 and 266 nm on aluminum target evolution, plasma generation, laser absorption in the plasma, and the plasma characteristic during laser ablation in the presence of atmospheric pressure. For 1064 nm radiation, the evaporation of the target surface stops earlier and the plasma formation time is later. The plasma has higher temperature as well as density and the hottest region is at the forefront of the plasma. The plasma shielding effect resulted in a sharp decrease in the laser transmissivity of 1064 nm radiation to about 0.1%, while the transmissivity of 266 nm radiation only decreased to about 30%. The inverse bremsstrahlung is the most important laser absorption mechanism for 1064 nm, whereas photoionization dominates the entire absorption process in the case of 266 nm radiation. The effect of the plasma model on optical breakdown has been present. The results show that neither breakdown nor plasma formation is encountered if the local thermodynamic equilibrium model is used in 266 nm radiation.

Probing red supergiant dynamics through photo-center displacements measured by Gaia

Context. Red supergiant (RSGs) are cool massive stars in a late phase of their evolution when the stellar envelope becomes fully convective. They are the brightest stars in the universe at infrared light and can be detected in galaxies far beyond the Local Group, allowing for accurate determination of chemical composition of galaxies. The study of their physical properties is extremely important for various phenomena including the final fate of massive stars as type II supernovae and gravitational wave progenitors. Aims. We explore the well-studied nearby young stellar cluster χ Per, which contains a relatively large population of RSG stars. Using Gaia EDR3 data, we find the distance of the cluster (d = 2.260 ± 0.020 kpc) from blue main sequence stars and compare with RSG parallax measurements analysing the parallax uncertainties of both groups. We then investigate the variability of the convection-related surface structure as a source for parallax measurement uncertainty. Methods. We use state-of-the-art three-dimensional radiative hydrodynamics simulations of convection with CO5BOLD and the post-processing radiative transfer code OPTIM3D to compute intensity maps in the Gaia G photometric system. We calculate the variabiltiy, as a function of time, of the intensity-weighted mean (or the photo-center) from the synthetic maps. We then select the RSG stars in the cluster and compare their uncertainty on parallaxes to the predictions of photocentre displacements. Results. The synthetic maps of RSG show extremely irregular and temporal variable surfaces due to convection-related dynamics. Consequentially, the position of the photo-center varies during Gaia measurements between 0.033 and 0.130 AU (≈1 to ≈5% of the corresponding simulation stellar radius). We argue that the variability of the convection-related surface structures accounts for a substantial part of the Gaia EDR3 parallax error of the RSG sample of χ Per. Conclusions. We suggest that the variation of the uncertainty on Gaia parallax could be exploited quantitatively using appropriate RHD simulations to extract, in a unique way, important information about the stellar dynamics and parameters of RSG stars.

Modeling the signatures of interaction in Type II supernovae: UV emission, high-velocity features, broad-boxy profiles

Because mass loss is a fundamental phenomenon in massive stars, an interaction with circumstellar material (CSM) should be universal in core-collapse supernovae (SNe). Leaving aside the extreme CSM density, extent, or mass typically encountered in Type IIn SNe, we investigate the diverse long-term radiative signatures of an interaction between a Type II SN ejecta and CSM corresponding to mass-loss rates up to 10−3 M⊙ yr−1. Because these CSM are relatively tenuous and optically thin to electron scattering beyond a few stellar radii, radiation hydrodynamics is not essential and one may treat the interaction directly as an additional power source in the non-local thermodynamic equilibrium radiative transfer problem. The CSM accumulated since shock breakout forms a dense shell in the outer ejecta and leads to high-velocity absorption features in spectral lines, even for a negligible shock power. In addition to Balmer lines, such features may appear in Na I D and He I lines, among others. A stronger interaction strengthens the continuum flux (preferentially in the UV), quenches the absorption of P-Cygni profiles, boosts the Mg IIλλ 2795, 2802 doublet, and fosters the production of a broad-boxy Hα emission component. The rise in ionization in the outer ejecta may quench some lines (e.g., the Ca II near-infrared triplet). The interaction power emerges preferentially in the UV, in particular at later times, shifting the optical color to the blue, but increasing the optical luminosity modestly. Strong thermalization and clumping seem to be required to make an interaction superluminous in the optical. The UV range contains essential signatures that provide critical constraints to infer the mass-loss history and inner workings of core-collapse SN progenitors at death.

Metal Mixing in Minihalos: The Descendants of Pair-instability Supernovae

The lack of observations of abundance patterns originating in pair-instability supernovae has been a long-standing problem in relation to the first stars. This class of supernovae is expected to have an abundance pattern with a strong odd–even effect, making it substantially different from present-day supernovae. In this study, we use a cosmological radiation hydrodynamics simulation to model such supernovae and the subsequent formation of the second generation of stars. We incorporate streaming velocities for the first time. There are 14 star-forming minihalos in our 1 cMpc h −1 box, leading to 14 supernovae occurring before redshift z = 19.5, where we start reducing the complexity of the simulation. Following the explosions, extremely metal-poor stars form in 10 halos via internal and external enrichment, which makes it the most common outcome. Only one halo does not recollapse during the simulations. This result is at variance with the current (lack of) observations of metal-poor stars with pair-instability supernova abundance patterns, suggesting that these very massive stars might be rare even in the early universe. The results from this simulation also give us insights into what drives different modes of recollapse and what determines the mixing behavior of metals after very energetic supernovae.

The 3D Dust and Opacity Distribution of Protoplanets in Multifluid Global Simulations

Abstract The abundance and distribution of solids inside the Hill sphere are central to our understanding of the giant planet dichotomy. Here, we present a 3D characterization of the dust density, mass flux, and mean opacities in the envelope of subthermal and superthermal-mass planets. We simulate the dynamics of multiple dust species in a global protoplanetary disk model accounting for dust feedback. We find that the meridional flows do not effectively stir dust grains at scales of the Bondi sphere. Thus the dust settling driven by the stellar gravitational potential sets the latitudinal dust density gradient within the planet envelope. Not only does the planet’s potential enhance this gradient, but also the spiral wakes serve as another source of asymmetry. These asymmetries substantially alter the inferred mean Rosseland and Planck opacities. In cases with moderate-to-strong dust settling, the opacity gradient can range from a few percent to more than two orders of magnitude between the midplane and the polar regions of the Bondi sphere. Finally, we show that this strong latitudinal opacity gradient can introduce a transition between optically thick and thin regimes at the scales of the planet envelope. We suggest that this transition is likely to occur when the equilibrium scale height of hundred-micron-sized particles is smaller than the Hill radius of the forming planet. This work calls into question the adoption of a constant opacity derived from well-mixed distributions and demonstrates the need for global radiation hydrodynamics models of giant planet formation that account for dust dynamics.

Crystallization and phase transitions of C6H6:C6F6 complex under extreme conditions using laser-driven shock

The C6H6:C6F6 cocrystal is one of the simplest organic cocrystals with a molecule having a C–F bond and without any hydrogen bonding. It has a crystal structure very different from its constituents, C6H6 and C6F6, and its higher melting point indicates its increased stability relative to these two materials. So far, no studies are available on the phase transitions of this interesting adduct under dynamic compression. In this study, we present the findings of phase transitions of an equimolar mixture of C6H6:C6F6 observed under rapid shock compression at pressures of up to 4.15 GPa using time-resolved Raman spectroscopy. The compression is driven by a 2 J Nd:YAG laser with an 8 ns pulse length. Four prominent modes at 370 cm−1 (ν10F mode), 443 cm−1 (ν6F mode), 560 cm−1 (ν1F mode), and 991 cm−1 (ν1H mode) exhibit a blue shift with scaling factors of 2.41, 2.26, 2.39, and 2.67 cm−1/GPa, respectively. The liquid → solid-I phase transition is observed at around 0.49 GPa shock pressure. The second phase transition from solid-I → solid-VI is observed between 1.32 and 2.60 GPa, and no signature of the solid-V phase is observed unlike in the case of static compression[Wang et al., J. Phys. Chem. C 120, 29510 (2016)]. Another phase transition solid-VI → solid-VII is observed between 3.9 and 4.15 GPa. The shock velocities in the sample at two laser intensities, 1.47 GW/cm2 (300 mJ) and 2.46 GW/cm2 (500 mJ), are calculated by measuring the intensity ratio of Raman modes emerging from the shocked region to that of the whole sample and are 3.13 and 4.05 km/s, respectively. To compare with the experimental results, 1D radiation hydrodynamics simulations are also performed. The experimental and simulated shock velocities are in good agreement. The mode Grüneisen parameter for the ν1H, ν1F, ν6F, ν10F, and ν10' F modes are γi = 0.011(2), 0.022(2), 0.011(1), 0.024(3), and 0.379(14), respectively.

OPTAB: Public code for generating gas opacity tables for radiation hydrodynamics simulations

We have developed a public code, OPTAB, that outputs Rosseland, Planck, and two-temperature Planck mean gas opacity tables for radiation hydrodynamics simulations in astrophysics. The code is developed for modern high-performance computing, being written in Fortran 90 and using Message Passing Interface and Hierarchical Data Format, Version 5. The purpose of this work is to provide a platform on which users can generate opacity tables for their own research purposes. Therefore, the code has been designed so that a user can easily modify, change, or add opacity sources in addition to those already implemented, which include bremsstrahlung, photoionization, Rayleigh scattering, line absorption, and collision-induced absorption. In this paper, we provide details of the opacity calculations in our code and present validation tests to evaluate the performance of our code.