熱楽

NETURAKU is an educational simulation app that allows users to interactively experience the physical phenomena of thermodynamics.

This is the fifth installment in the series, following SUUGAKU (Mathematics), BUTURAKU (Physics), DENRAKU (Electronics), and HARAKU (Waves). This time, the theme is "heat." Through 10 simulations, you can learn about the mysteries of heat and the profoundness of its physical laws while having fun.

【10 Simulations】

1. Particle Motion (Ideal Gas)
Observe the motion of particles in response to temperature in real time. By changing the volume and temperature, you can measure pressure from collisions with walls and experience the law of ideal gases (PV = nRT).

2. Heat Conduction
Simulate heat diffusion using the 2D finite difference method. By changing the temperature and thermal conductivity of the heat source, you can observe the change in temperature distribution based on Fourier's law in real time.

3. Phase Transition
Changing the temperature changes the state from solid to liquid to gas. You can intuitively experience the differences in particle behavior, from lattice vibrations to free motion. You can visually understand the concepts of melting and boiling points.

4. Carnot Cycle
You can track the four processes of isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression on a PV diagram and visualize the efficiency of an ideal heat engine (η = 1 - T_L/T_H).

5. Entropy
Simulate the mixing process of two gases separated by a partition. You can observe in real time on a graph how entropy increases when the partition is removed.

6. Thermal Radiation/Blackbody Radiation
Visualize the blackbody radiation spectrum (Planck distribution) according to temperature in real time. You can experience how the peak wavelength shifts when the temperature changes (Wien's displacement law) and how the radiant energy is proportional to the fourth power of the temperature (Stefan-Boltzmann law).

7. Velocity Distribution (Maxwell-Boltzmann Distribution)
Simultaneously displays the velocity distribution of gas particles using a histogram and theoretical curve. Observe how the distribution widens and the peak shifts to the right as the temperature increases. This allows for an intuitive understanding of the relationship between the mode velocity, mean velocity, and mean square velocity.

8. Brownian Motion
Visualizes the irregular motion of large particles (pollen particles) as they collide with numerous invisible, tiny molecules. The trajectory is plotted in real time, allowing observation of random walk-like paths and changes in motion due to temperature and the number of molecules.

9. Cooling Law (Newton's Law of Cooling)
Simulates how a high-temperature object cools in proportion to its temperature difference with the surroundings. By changing the cooling coefficient, initial temperature, and ambient temperature, observe the process by which the exponential decay curve of the temperature-time graph asymptotically approaches the ambient temperature.

10. Diffusion (Fick's Law)
This simulation depicts the diffusion of a substance, like a drop of ink, spreading from areas of high concentration to areas of low concentration to become uniform. You can add ink by tapping, and observe how the concentration profile in the central cross-section changes, becoming "lower and wider (towards uniformity)."

[Features]
• Real-time parameter adjustment for all simulations
• Real-time display of physical formulas and numerical values
• Dark mode / Light mode support
• Easy-to-view home screen organized by category
• Intuitive and beautiful UI
• Ads are limited to banners at the bottom of the screen
• No in-app purchases or subscriptions

[Recommended for:]
• Students studying thermodynamics and statistical mechanics in physics classes
• Those who want to intuitively understand the properties of heat
• Teachers who want to use it as teaching material
• Anyone interested in thermodynamics and statistical physics