Merge pull request #25 from ngomezve/layout_dev

Cabin layout and cryogenic fuel properties
MIT-LAE · Mar 27, 2024 · e70d62b · e70d62b
2 parents b7f7f0e + 8906ba4
commit e70d62b
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diff --git a/example/cryo_input.toml b/example/cryo_input.toml
@@ -44,14 +44,11 @@ name = "TASOPT Model with cryo fuel and HX"
     prop_sys_arch = "TF" #Options are TF: Turbofan
                          #            TE: Turbo-electric
 [Fuel]
-    fuel_type       = "LH2" # Choices are ... [TODO]
+    fuel_type       = "LH2" # Choices are "Jet-A", "LH2" and "CH4"
     fuel_in_wing    = false # Is fuel stored in wings?
     fuel_in_wingcen = false # Is fuel stored in wing center box?
     fuel_usability_factor = 0.90 # fraction of max fuel volume that is usable
 
-    fuel_temp = 20.0
-    fuel_density = 70.0 #kg/m3
-
 [Fuel.Storage]
     tank_placement = "front" #Location of tank in fuselage. Choices are "front", "rear", or "both".
     insulation_segment_base_thickness = [0.05,0.05,0.05] #m

diff --git a/src/IO/default_input.toml b/src/IO/default_input.toml
@@ -46,7 +46,7 @@
     prop_sys_arch = "TF" #Options are TF: Turbofan
                          #            TE: Turbo-electric
 [Fuel]
-    fuel_type       = "Jet-A" # Choices are ... [TODO]
+    fuel_type       = "Jet-A" # Choices are "Jet-A", "LH2" and "CH4"
     fuel_in_wing    = true # Is fuel stored in wings?
     fuel_in_wingcen = true # Is fuel stored in wing center box?
     fuel_usability_factor = 0.90 # fraction of max fuel volume that is usable
@@ -142,6 +142,11 @@
     #Use provided layout (false) or recalculate it (true) for design pax keeping deltas
     calculate_cabin_length = false 
 
+    double_decker   = false #if true, the fuselage has two passenger decks
+    seat_pitch      = "30 in"
+    seat_width      = "19 in"
+    aisle_halfwidth = "10 in"
+
     #Provided layout
     x_nose_tip           = "0 ft"
     x_pressure_shell_fwd = "17 ft"

diff --git a/src/IO/read_input.jl b/src/IO/read_input.jl
@@ -2,6 +2,7 @@ using TOML
 export read_aircraft_model, load_default_model
 
 include("size_cabin.jl")
+include("../fuel/fuel_properties.jl")
 #using ..structures
 
 """
@@ -143,19 +144,22 @@ fueltype = readfuel("fuel_type")
 #TODO this needs to be updated once I include Gas.jl into TASOPT
 if uppercase(fueltype) == "LH2"
     pari[iifuel] = 40
+
 elseif uppercase(fueltype) == "CH4"
-        pari[iifuel] = 11
+    pari[iifuel] = 11
+
 elseif uppercase(fueltype) == "JET-A"
     pari[iifuel] = 24
+
+    pare[ieTft, :, :] .= readfuel("fuel_temp") #Temperature of fuel in fuel tank
+    pare[ieTfuel, :, :] .= readfuel("fuel_temp") #Initialize fuel temperature as temperature in tank
+    parg[igrhofuel] = readfuel("fuel_density")
 else
     error("Check fuel type")
 end
 pari[iifwing]  = readfuel("fuel_in_wing")
 pari[iifwcen]  = readfuel("fuel_in_wingcen")
 parg[igrWfmax] = readfuel("fuel_usability_factor")
-pare[ieTft, :, :] .= readfuel("fuel_temp") #Temperature of fuel in fuel tank
-pare[ieTfuel, :, :] .= readfuel("fuel_temp") #Initialize fuel temperature as temperature in tank
-parg[igrhofuel] = readfuel("fuel_density")
 
 #Fuel storage options
 fuse_tank = fuselage_tank() #Initialize struct for fuselage fuel tank params
@@ -184,6 +188,12 @@ if pari[iifwing]  == 0 #If fuel is stored in fuselage
     elseif (fuse_tank.placement == "both") 
         pari[iinftanks] = 2
     end
+
+    #Calculate fuel temperature and density as a function of pressure
+    Tfuel, ρfuel = cryo_fuel_properties(uppercase(fueltype), fuse_tank.ptank)
+    pare[ieTft, :, :] .= Tfuel #Temperature of fuel in fuel tank
+    pare[ieTfuel, :, :] .= Tfuel #Initialize fuel temperature as temperature in tank
+    parg[igrhofuel] = ρfuel
 end
 
 # Setup mission variables
@@ -306,10 +316,14 @@ readgeom(x) = read_input(x, geom, dgeom)
     #after loading the wing and stabilizer positions
     calculate_cabin = readgeom("calculate_cabin_length") 
 
+    parg[igseatpitch] = Distance(readgeom("seat_pitch"))
+    parg[igseatwidth] = Distance(readgeom("seat_width"))
+    parg[igaislehalfwidth] = Distance(readgeom("aisle_halfwidth"))
+
     parg[igRfuse]  = Distance(readgeom("radius"))
     parg[igdRfuse] = Distance(readgeom("dRadius"))
     parg[igwfb]    = Distance(readgeom("y_offset"))
-    parg[ighfloor] = Distance(readgeom("floor_depth")) 
+    parg[ighfloor] = Distance(readgeom("floor_depth"))
     parg[ignfweb]  = readgeom("Nwebs")
 
     parg[iganose] = readgeom("a_nose")
@@ -866,4 +880,4 @@ end
 function load_default_model()
     println("Loading default aircraft model")
     read_aircraft_model()
-end
+end
diff --git a/src/IO/size_cabin.jl b/src/IO/size_cabin.jl
@@ -14,10 +14,9 @@ length.
     - `xseats::Vector{Float64}`: longitudinal coordinate of each row of seats, measured from front of cabin (m).
     - `seats_per_row::Float64`: number of seats per row.
 """
-function place_cabin_seats(pax, Rfuse)
-    seat_pitch = 30.0 * in_to_m 
-    seat_width = 19.0 * in_to_m
-    aisle_halfwidth = 10.0 * in_to_m # per CFR § 25.815 
+function place_cabin_seats(pax, Rfuse, seat_pitch = 30.0*in_to_m, 
+    seat_width = 19.0*in_to_m, aisle_halfwidth = 10.0*in_to_m)
+
     cabin_offset = 10 * ft_to_m #Distance to the front and back of seats
     #TODO the hardcoded 10 ft is not elegant
 

diff --git a/src/fuel/fuel_properties.jl b/src/fuel/fuel_properties.jl
@@ -0,0 +1,25 @@
+"""
+    cryo_fuel_properties(fuel::String, p::Float64)
+
+Calculates the temperature and density of a cryogenic fuel inside a tank, using fits to data from NIST.
+!!! details "🔃 Inputs and Outputs"
+    **Inputs:**
+    - `fuel::String`: name of the fuel. 
+    - `p::String`: tank pressure (Pa).
+    **Outputs:**
+    - `Tfuel::Float64`: fuel evaporation temperature (K) 
+    - `ρfuel::String`: density of fuel (kg/m^3).
+"""
+function cryo_fuel_properties(fuel::String, p::Float64)
+    x = p / 101325 #pressure in atm
+
+    #Fits to NIST data at p = [0.5,1,1.5,2,2.5,3,4,5,10] atm
+    if fuel == "LH2" 
+        Tfuel = 20.3839 * x^0.182022 
+        ρfuel = -2.88304E-02*x^3 + 4.93319E-01*x^2 - 4.61334E+00*x + 7.51570E+01
+    elseif fuel == "CH4"
+        Tfuel = 111.69030 * x^0.12093
+        ρfuel = -1.49198E-01*x^3 + 2.85956E+00*x^2 - 2.20464E+01*x + 4.42724E+02
+    end
+    return Tfuel, ρfuel
+end
diff --git a/src/misc/index.inc b/src/misc/index.inc
@@ -374,13 +374,18 @@
       const igTfuel      = 301
 
       const igxftankaft  = 302
-      const igdxcabin  = 303
+      const igdxcabin    = 303
       const igdxeng2wbox = 304
 
       const igxWfuel = 305
-      const igmdotboiloff = 306
 
-      const igtotal    = 306
+      const igseatpitch = 306
+      const igseatwidth = 307
+      const igaislehalfwidth = 308
+
+      const igmdotboiloff = 309
+
+      const igtotal    = 309
 
 # indices for turbo-electric systems - really just the electrical machines
       const ite_ratSM   = 1

diff --git a/src/structures/update_fuse.jl b/src/structures/update_fuse.jl
@@ -70,8 +70,11 @@ It sizes the cabin for the design number of passengers.
 """
 function update_fuse_for_pax!(pari, parg, parm, fuse_tank)
 
-    despax = parm[imWpay,1]/parm[imWperpax,1] #design number of passengers
+    seat_pitch = parg[igseatpitch]
+    seat_width = parg[igseatwidth]
+    aisle_halfwidth = parg[igaislehalfwidth]
 
+    maxpax = parg[igWpaymax]/parm[imWperpax,1] #maximum number of passengers
     #Useful relative distances to conserve
     dxeng2wbox = parg[igdxeng2wbox] #Distance from engine to wingbox
     dxcyl2shellaft = parg[igxshell2] - parg[igxblend2] #Distance from blend2 to shell2
@@ -84,7 +87,7 @@ function update_fuse_for_pax!(pari, parg, parm, fuse_tank)
     wbox_cabin_frac =  (parg[igxwbox]- parg[igxblend1] )/(parg[igxblend2] - parg[igxblend1]) 
 
     #Find new cabin length
-    lcyl, _, _ = place_cabin_seats(despax, parg[igRfuse]) #Size for design pax count
+    lcyl, _, _ = place_cabin_seats(maxpax, parg[igRfuse], seat_pitch, seat_width, aisle_halfwidth) #Size for max pax count
 
     #When there is a fuel tank at the back of the fuselage, there is no offset between the end of the seat rows
     #and the start of the tank. For this reason, leave a 5ft offset at back

diff --git a/test/default_sized.jl b/test/default_sized.jl
@@ -330,6 +330,9 @@ parg[302] = 0.00000000000000000000 # igxftankaft
 parg[303] = 23.4696 # igdxcabin
 parg[304] = 1.52399999999999 # igdxeng2wbox
 parg[305] = 4.0885967681724094e6 #igxWfuel
+parg[306] = 0.762 #igseatpitch
+parg[307] = 0.4826 #igseatwidth
+parg[308] = 0.254 #igaislehalfwidth
 
 # --------------------------------
 # Mission  - stored in parm array:

diff --git a/test/regional_sized.jl b/test/regional_sized.jl
@@ -331,7 +331,9 @@ parg[302] = 0.00000000000000000000
 parg[303] = 24.99360000000000070486 
 parg[304] = 2.43839999999999790248 
 parg[305] = 1555504.53431817726232111454 
-parg[306] = 0.00000000000000000000 
+parg[306] = 0.762 #igseatpitch
+parg[307] = 0.4826 #igseatwidth
+parg[308] = 0.254 #igaislehalfwidth
 # --------------------------------
 # Mission  - stored in parm array:
 # --------------------------------

diff --git a/test/wide_sized.jl b/test/wide_sized.jl
@@ -331,7 +331,9 @@ parg[302] = 0.00000000000000000000
 parg[303] = 39.92880000000000251248 
 parg[304] = 3.65759999999999863007 
 parg[305] = 51085067.57496136426925659180 
-parg[306] = 0.00000000000000000000 
+parg[306] = 0.762 #igseatpitch
+parg[307] = 0.4826 #igseatwidth
+parg[308] = 0.254 #igaislehalfwidth
 # --------------------------------
 # Mission  - stored in parm array:
 # --------------------------------