Numerička analiaza izgaranja smjese metan –vodik u cilindru za različita vremena bacanja iskre

In this study, numerical simulations of combustion characteristics using pure methane and 70 % CH4-30 % H2 blends were investigated in a spark ignition engine. The numerical calculations were performed using the finite volume CFD code FLUENT with standard k-ε model using the compression ratio and the engine speed are 10 and 2000 rpm respectively. Excess air ratios were selected as 1, 1.2 and 1.4. The spark timings were started at 45, 30 and 15 degree crank angle (CA) before top dead center (BTDC). The results of the combustion process were investigated as a function of crank angle. The maximum cylinder pressures and temperatures were obtained with 70 % CH4-30 % H2 mixture. It is observed that peak pressure values are decreased when the excess air ratio increased.U ovom se radu numerički simuliraju karakteristike izgaranja čistog metana i smjese 70 % CH4 i 30 % H2 kod motora paljenih sa svjećicom. Numerički proračuni su napravljeni koristeći kontrolni volumen CFD, kod FLUENT, sa standardnim k – ε modelom koristeći kompresijski omjer i brzinu motora 10 i 2000 min-1. Odabrani faktori pretička zraka su 1, 1.2 I 1.4. Vrijeme početka paljenja iskrom odgovaralo je 45, 30 i 15 stupnjeva koljenastog vratila prije gornje mrtve točke. Reultati procesa izgaranja su istraživani u ovisnosti o kutu pretpaljenja. Utvrđeni su maksimalni tlakovi u cilindru za smjesu 70 % CH4 i 30 % H2. Uočeno je da se smanjuju vrijednosti maksimalnog tlaka s povećavanjem faktora pretička zraka

Numerical analyses of combustion methane-hydrogen mixtures in cylinder for different spark timing

In this study, numerical simulations of combustion characteristics using pure methane and 70 % CH4-30 % H2 blends were investigated in a spark ignition engine. The numerical calculations were performed using the finite volume CFD code FLUENT with standard k-ε model using the compression ratio and the engine speed are 10 and 2000 rpm respectively. Excess air ratios were selected as 1, 1.2 and 1.4. The spark timings were started at 45, 30 and 15 degree crank angle (CA) before top dead center (BTDC). The results of the combustion process were investigated as a function of crank angle. The maximum cylinder pressures and temperatures were obtained with 70 % CH 4-30 % H2 mixture. It is observed that peak pressure values are decreased when the excess air ratio increased