def Yun_Heo_Kim(m, x, D, rhol, mul, Hvap, sigma, q=None, Te=None): r'''Calculates heat transfer coefficient for film boiling of saturated fluid in any orientation of flow. Correlation is as shown in [1]_ and [2]_, and also reviewed in [3]_. Either the heat flux or excess temperature is required for the calculation of heat transfer coefficient. Uses liquid Reynolds number, Weber number, and Boiling number. Weber number is defined in terms of the velocity if all fluid were liquid. .. math:: h_{tp} = 136876(Bg\cdot We_l)^{0.1993} Re_l^{-0.1626} .. math:: Re_l = \frac{G D (1-x)}{\mu_l} .. math:: We_l = \frac{G^2 D}{\rho_l \sigma} Parameters ---------- m : float Mass flow rate [kg/s] x : float Quality at the specific tube interval [] D : float Diameter of the tube [m] rhol : float Density of the liquid [kg/m^3] mul : float Viscosity of liquid [Pa*s] Hvap : float Heat of vaporization of liquid [J/kg] sigma : float Surface tension of liquid [N/m] q : float, optional Heat flux to wall [W/m^2] Te : float, optional Excess temperature of wall, [K] Returns ------- h : float Heat transfer coefficient [W/m^2/K] Notes ----- [1]_ has been reviewed. Examples -------- >>> Yun_Heo_Kim(m=1, x=0.4, D=0.3, rhol=567., mul=156E-6, sigma=0.02, Hvap=9E5, q=1E4) 9479.313988550184 References ---------- .. [1] Yun, Rin, Jae Hyeok Heo, and Yongchan Kim. "Evaporative Heat Transfer and Pressure Drop of R410A in Microchannels." International Journal of Refrigeration 29, no. 1 (January 2006): 92-100. doi:10.1016/j.ijrefrig.2005.08.005. .. [2] Yun, Rin, Jae Hyeok Heo, and Yongchan Kim. "Erratum to 'Evaporative Heat Transfer and Pressure Drop of R410A in Microchannels; [Int. J. Refrigeration 29 (2006) 92-100]." International Journal of Refrigeration 30, no. 8 (December 2007): 1468. doi:10.1016/j.ijrefrig.2007.08.003. .. [3] Bertsch, Stefan S., Eckhard A. Groll, and Suresh V. Garimella. "Review and Comparative Analysis of Studies on Saturated Flow Boiling in Small Channels." Nanoscale and Microscale Thermophysical Engineering 12, no. 3 (September 4, 2008): 187-227. doi:10.1080/15567260802317357. ''' G = m/(pi/4*D**2) V = G/rhol Rel = G*D*(1-x)/mul We = Weber(V=V, L=D, rho=rhol, sigma=sigma) if q is not None: Bg = Boiling(G=G, q=q, Hvap=Hvap) return 136876*(Bg*We)**0.1993*Rel**-0.1626 elif Te is not None: A = 136876*(We)**0.1993*Rel**-0.1626*(Te/G/Hvap)**0.1993 return A**(10000/8007.) else: raise ValueError('Either q or Te is needed for this correlation')
def Sun_Mishima(m, D, rhol, rhog, mul, kl, Hvap, sigma, q=None, Te=None): r'''Calculates heat transfer coefficient for film boiling of saturated fluid in any orientation of flow. Correlation is as shown in [1]_, and also reviewed in [2]_. Either the heat flux or excess temperature is required for the calculation of heat transfer coefficient. Uses liquid-only Reynolds number, Weber number, and Boiling number. Weber number is defined in terms of the velocity if all fluid were liquid. .. math:: h_{tp} = \frac{ 6 Re_{lo}^{1.05} Bg^{0.54}} {We_l^{0.191}(\rho_l/\rho_g)^{0.142}}\frac{k_l}{D} .. math:: Re_{lo} = \frac{G_{tp}D}{\mu_l} Parameters ---------- m : float Mass flow rate [kg/s] D : float Diameter of the tube [m] rhol : float Density of the liquid [kg/m^3] rhog : float Density of the gas [kg/m^3] mul : float Viscosity of liquid [Pa*s] kl : float Thermal conductivity of liquid [W/m/K] Hvap : float Heat of vaporization of liquid [J/kg] sigma : float Surface tension of liquid [N/m] q : float, optional Heat flux to wall [W/m^2] Te : float, optional Excess temperature of wall, [K] Returns ------- h : float Heat transfer coefficient [W/m^2/K] Notes ----- [1]_ has been reviewed. [1]_ used 2501 data points to derive the results, covering hydraulic diameters from 0.21 to 6.05 mm and 11 different fluids. Examples -------- >>> Sun_Mishima(m=1, D=0.3, rhol=567., rhog=18.09, kl=0.086, mul=156E-6, sigma=0.02, Hvap=9E5, Te=10) 507.6709168372167 References ---------- .. [1] Sun, Licheng, and Kaichiro Mishima. "An Evaluation of Prediction Methods for Saturated Flow Boiling Heat Transfer in Mini-Channels." International Journal of Heat and Mass Transfer 52, no. 23-24 (November 2009): 5323-29. doi:10.1016/j.ijheatmasstransfer.2009.06.041. .. [2] Fang, Xiande, Zhanru Zhou, and Dingkun Li. "Review of Correlations of Flow Boiling Heat Transfer Coefficients for Carbon Dioxide." International Journal of Refrigeration 36, no. 8 (December 2013): 2017-39. doi:10.1016/j.ijrefrig.2013.05.015. ''' G = m/(pi/4*D**2) V = G/rhol Relo = G*D/mul We = Weber(V=V, L=D, rho=rhol, sigma=sigma) if q is not None: Bg = Boiling(G=G, q=q, Hvap=Hvap) return 6*Relo**1.05*Bg**0.54/(We**0.191*(rhol/rhog)**0.142)*kl/D elif Te is not None: A = 6*Relo**1.05/(We**0.191*(rhol/rhog)**0.142)*kl/D return A**(50/23.)*Te**(27/23.)/(G**(27/23.)*Hvap**(27/23.)) else: raise ValueError('Either q or Te is needed for this correlation')