Module:Gas

Documentation for this module can be edited at Module:Gas/doc

Methods

GetGas

Use: GetGas(User input)

Returns a read-only Gas object containing information for a given gas.

If no gas is found that can match the input, throws an error.

Phase change methods

Evaporation Pressure

EvaporationPressureUnclamped

Use: EvaporationPressureClamped(gasTable, Temperature)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Temperature: The current gas gemperature in kelvin

Evaluates the gas's evaporation pressure curve for a given Temperature, returning its corresponding evaporation pressure in kPa. This is just the curve function without any compensation for phase change characteristics.

EvaporationPressureClamped

Use: EvaporationPressureUnclamped(gasTable, Temperature)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Temperature: The current gas gemperature in kelvin

Evaluates the gas's evaporation pressure curve for a given Temperature, returning its corresponding evaporation pressure in kPa. Unlike EvaporationPressureClamped, this first clamps the input temperature to values within the range where the gas can exist as a non-frozen liquid.

EvaporationPressure

Use: EvaporationPressure(gasTable, Temperature)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Temperature: The current gas gemperature in kelvin

Evaluates the gas's evaporation pressure curve for a given Temperature, returning its corresponding evaporation pressure in kPa. Unlike the other methods, this provides additional handling to return the evaporation pressure for supercooled liquids when given a liquid as input.

Evaporation Temperature

EvaporationTemperatureUnclamped

Use: EvaporationPressureUnclamped(gasTable, Pressure)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Pressure: The current gas pressure in kPa

Evaluates the gas's evaporation pressure curve for a given Pressure, returning its corresponding evaporation temperature in kelvin. This is just the curve function without any compensation for phase change characteristics.

EvaporationTemperatureClamped

Use: EvaporationTemperatureClamped(gasTable, Pressure)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Pressure: The current gas pressure in kPa

Evaluates the gas's evaporation pressure curve for a given Pressure, returning its corresponding evaporation temperature in kelvin. Pressure values are clamped to the range of values the gas can exist as a non-frozen, non-supercritical liquid.

EvaporationTemperature

Use: EvaporationTemperatureClamped(gasTable, Temperature)
gasTable: a table containing information for a given gas (obtainable through GetGas)
Pressure: The current gas pressure in kPa

Evaluates the gas's evaporation pressure curve for a given Pressure, returning its corresponding evaporation temperature in kelvin. This is currently the same as EvaporationTemperatureUnclamped(gasTable, Pressure).

Objects

Gas

A table containing data for a gas. Editing these should be done through Module:Gas/data.

Fields

See Module:Gas/data/doc.

---

--Wikitext methods:
--Infobox(GasName): Creates an infobox for the gas type. (NYI)

--Lua methods:
--GetGas(?): Try to find a gas matching the input. Returns a table containing data for that gas or throws an error.

--EvaporationPressureClamped(gas, Temperature(K)): Calculates the evaporation pressure for a gas.
--EvaporationPressureUnclamped(gas, Temperature(K)): Calculates the evaporation pressure for a gas while ignoring curve values.
--EvaporationPressure(gas, Temperature(K)): Calculates the actual evaporation pressure for a gas ingame as neither Clamped nor Unclamped values are used

--EvaporationTemperatureUnclamped(gas, Pressure(kPa)): Calculates the evaporation temperature for a gas while ignoring pressure limits.
--EvaporationTemperatureClamped(gas, Pressure(kPa)): Calculates the evaporation temperature for a gas.
--EvaporationTemperature(gas, Pressure(kPa)[, Temperature(K)]): Currently the same as EvaporationTemperatureClamped.

local GasData = mw.loadData("Module:Gas/data")




local p = {}

local function GetGas(input)
    --Attempts to get a Gas object from user input.
    if input == nil then return nil end

    --Frame handling
    if type(input)=="table" and type(input.args)=="table" then return GetGas(p.args.Name) or GetGas(p.args[1]) or GetGas(p.args[2]) or GetGas(p.args[3]) end

    --Gas handling
    if type(input)=="table" and type(input.Name)=="String" and type(input.State)=="String" and type(input.MolarMass)=="number" then return input end

    --Number handling
    if type(input)=="number" then return GasData[input] or error("Could not find GasData for Gas number: "..input) end
    
    --String handling
    if type(input)=="string" then
        -- See if there's a direct name match
        if type(GasData[input])=="table" and GasData[input].Name == input then return GasData[input] end

        -- search for human readable names
        for k,v in pairs(GasData.HumanReadableName) do
            if v==input then return GetGas(k) end
        end

        -- search for human readable symbols, preferring gases first
        local LiquidWithSymbol
        for k,v in pairs(GasData.HumanReadableSymbol) do
            if v==input and GasData[k].State=="Gas" then return p.GetGas(k) end
            if v==input and GasData[k].State=="Liquid" then LiquidWithSymbol = k end
        end
        if LiquidWithSymbol then return GetGas(LiquidWithSymbol) end

        -- Hail mary: Try to find a liquid version of the gas.
        if input:sub(1,6)=="Liquid" then error("Could not find GasData for gas: "..input) end --fail if we're already doing that

        -- If there's a space in our name we'll probably have better luck by also using a space.
        if string.match(input, " .") then return p.GetGas("Liquid "..input) else return p.GetGas("Liquid"..input) end

    end
  
end
p.GetGas = GetGas

local function EvaporationPressureUnclamped(gas, Temperature) -- Evaporation pressure using exponential curve
    return gas.A*(Temperature^Gas.B)
end
p.EvaporationPressureUnclamped = EvaporationPressureUnclamped 

local function Clamp(value, min, max) --helper function. Not sure if this should be added into the global math library.
    if value<min then return min end
    if value>max then return max end
    return value
end

local function EvaporationPressureClamped(gas, Temperature) --Evaporation pressure using stationpedia curve
    Temperature = Clamp(Temperature,gas.FreezingTemperature, gas.CriticalTemperature)
    return EvaporationPressureUnclamped(gas, Temperature)
end
p.EvaporationPressureClamped = EvaporationPressureClamped

local function MapToScale(min, max, outMin, outMax, value) --Helper function, maps to RocketMath.MapToScale
    local inputRange = max-min
    local outputRange = outMax-outMin
    return (value-min) * outputRange / inputRange + outMin
end

local function EvaporationPressure(gas, Temperature) --Evaporation pressure using actual ingame curve
   if gas.State == "Liquid" and Temperature < gas.FreezingTemperature then --Frozen gases still follow EvaporationPressureClamped
     Temperature = math.max(gas.FreezingTemperature/2, Temperature)
     return MapToScale(gas.FreezingTemperature/2, gas.FreezingTemperature, GasData.ArmstrongLimit, gas.TriplePressure, Temperature)
   else return EvaporationPressureClamped(gas, Temperature)
   end
end
p.EvaporationPressure = EvaporationPressure

local function EvaporationTemperatureUnclamped(gas, Pressure) --Evaporation temperature using exponential curve
    return (Pressure/gas.A) ^ (1/gas.B)
end

local function EvaporationTemperatureClamped(gas, Pressure) --Evaporation temperature using stationpedia curve
    Pressure = Clamp(Pressure, gas.TriplePressure, gas.CriticalPressure)
    return EvaporationTemperatureClamped(gas, Pressure)
end

local function Lerp(a,b,x)
    return a+(b-a)*Clamp(t,0,1)
end

--[[local function EvaporationTemperature(gas, Pressure, Temperature) -- Evaporation temperature using actual ingame rules. 
    Temperature = Temperature or gas.Temperature --It depends on the gas's own temperature for liquids.
    if gas.State == "Gas" or not Temperature then
        return EvaporationTemperatureClamped(gas, Pressure) --placeholder, unchecked 
    else--if gas.State == "Liquid" then
       if Temperature > gas.CriticalTemperature then return EvaporationTemperatureClamped(gas, Pressure) end
       if Temperature < gas.FreezingTemperature+1 and Temperature > gas.FreezingTemperature/2+1 then return Temperature-0.5 end
       local evaporationtemperature = EvaporationPressure(gas, Temperature)
       return Lerp(Temperature, Temperature-10, (EvaporationPressure(gas, Temperature)-Pressure)/TriplePointPressure)
    end
        error("Invalid Gas State")

end--]]--
--The method above doesn't make much sense yet because it's used for calculating evaporation energy limits instead of an actual evaporation temperature.
--Until it's actually used a simpler approach for evaporation(with the full one better done on an entirely separate atmospheric simulation module) may be better suited.

local EvaporationTemperature = EvaporationTemperatureClamped
p.EvaporationTemperature = EvaporationTemperature

return p