G'ovak muhitlar tenglamasi
G'ovak muhitlar tenglamasi yoki nochiziqli issiqlik tenglamasi deb quyidagi nochiziqli xususiy hosilali differensial tenglamaga aytiladi ∂ u ∂ t = Δ ( u m ) , m > 1 {\displaystyle {{\cfrac {\partial u}{\partial t}}=\Delta \left(u^{m}\right),\;m>1}} bu yerda Δ {\displaystyle \Delta } Laplas operatori. Shuningdek, yuqoridagi tenglamani quyidagicha, divergent ko'rinishda ham yozish mumkin ∂ u ∂ t = ∇ ⋅ [ D ( u ) ∇ u ] {\displaystyle {\partial u \over {\partial t}}=\nabla \cdot \left[D(u)\nabla u\right]} bu yerda D u = m u m − 1 {\displaystyle Du=mu^{m-1}} diffuziya koeffitsienti va ∇ ⋅ ( ⋅ ) {\displaystyle \nabla \cdot (\cdot )} divergensiya operatori.