100
4 Results and Discussion
348V CO 2 = H (Metabolic rate of the motorcyclist in tropical conditions) 428.35 W
h c = Convective coefficient (for 55 kph speed)
32.44 W/m 2 K
f cl = Ratio of surface area of clothed body to nude body
1.05
A d = DuBois body area for an adult (of weight 70 kg and height 1.73 m) 1.84 m 2
ε sk = Emissivity of the skin
0.97
ζ = Proportion of the unclothed body exposed to convection
0.05
ξ = Proportion of the clothed body exposed to convection
0.95
T sk = Temperature of the skin
307 °K
T a = Ambient temperature
301 °K
T cl =Temperature of the outside surface of the clothing
303 °K
Using the above equation and the value of each parameter as shown above, the
calculated value for convection (C) = 144.5 W.
4.4.1.4 Evaporation (E)
According to Eq. 3.11 as given in Sect. 3.8
V CO2 = Rate of CO2 respiration = H/348 [derived from the equation H = 348 V CO2] 1.23 l/min
h e = Evaporative coefficient (for 55 kph speed)
32.44 W/m 2 K
A d = DuBois body area for an adult (of weight 70 kg and height 1.73 m)
1.84 m 2
ω = Decimal proportion of the body that is wet from perspiration
0.1
ζ = Proportion of the unclothed body exposed to evaporation
0.05
ξ = Proportion of the clothed body exposed to evaporation
0.95
a = Cox chart curve fit coefficients for vapour pressure
0.014371
b = Cox chart curve fit coefficients for vapour pressure
– 3.11244
f pcl = Permeation efficiency of clothing (approx.)
1
T sk = Temperature of the skin
307 °K
T c = Core body temperature
310.15 °K
T dp = Dew point
288 °K
Using the above equation and the value of each parameter as shown above, the
calculated value for evaporation (E) = 208.6 W.
4.4.1.5 Thermal Balance
The thermal balance equation for human thermal regulation is given in Sect. 3.8
and Eq. 3.5 where, for tropical climates K, C and R values are taken to be negative.
Therefore, the thermal balance equation becomes:
4 Results and Discussion
348V CO 2 = H (Metabolic rate of the motorcyclist in tropical conditions) 428.35 W
h c = Convective coefficient (for 55 kph speed)
32.44 W/m 2 K
f cl = Ratio of surface area of clothed body to nude body
1.05
A d = DuBois body area for an adult (of weight 70 kg and height 1.73 m) 1.84 m 2
ε sk = Emissivity of the skin
0.97
ζ = Proportion of the unclothed body exposed to convection
0.05
ξ = Proportion of the clothed body exposed to convection
0.95
T sk = Temperature of the skin
307 °K
T a = Ambient temperature
301 °K
T cl =Temperature of the outside surface of the clothing
303 °K
Using the above equation and the value of each parameter as shown above, the
calculated value for convection (C) = 144.5 W.
4.4.1.4 Evaporation (E)
According to Eq. 3.11 as given in Sect. 3.8
V CO2 = Rate of CO2 respiration = H/348 [derived from the equation H = 348 V CO2] 1.23 l/min
h e = Evaporative coefficient (for 55 kph speed)
32.44 W/m 2 K
A d = DuBois body area for an adult (of weight 70 kg and height 1.73 m)
1.84 m 2
ω = Decimal proportion of the body that is wet from perspiration
0.1
ζ = Proportion of the unclothed body exposed to evaporation
0.05
ξ = Proportion of the clothed body exposed to evaporation
0.95
a = Cox chart curve fit coefficients for vapour pressure
0.014371
b = Cox chart curve fit coefficients for vapour pressure
– 3.11244
f pcl = Permeation efficiency of clothing (approx.)
1
T sk = Temperature of the skin
307 °K
T c = Core body temperature
310.15 °K
T dp = Dew point
288 °K
Using the above equation and the value of each parameter as shown above, the
calculated value for evaporation (E) = 208.6 W.
4.4.1.5 Thermal Balance
The thermal balance equation for human thermal regulation is given in Sect. 3.8
and Eq. 3.5 where, for tropical climates K, C and R values are taken to be negative.
Therefore, the thermal balance equation becomes: