TECHNICAL UNIVERSITY OF BUDAPEST 
                                        Faculty of Mechanical Engineering    
                                                           
                
                
                
                
                
                
                
                                       Internal Combustion Engines 
                                                   (Heat Engines II.) 
                
                                        Lecture note for the undergraduate course 
                                                      7th Semester 
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                                                              
                            Dr. Antal Penninger, Ferenc Lezsovits, János Rohály, Vilmos Wolff 
                                                          1995. 
                                               Revised: Dr. Ákos Bereczky 
                                                          2006 
                
                                                              
                                                                                                            
                                                                     
                               CLASSIFICATION OF INTERNAL COMBUSTION ENGINES 
                  
                 Principle of operation 
                     •   four stroke engine or 
                     •   two stroke engine 
                     •   other 
                  
                 Charging system 
                     •   Naturally aspirated 
                     •   Mechanically charged 
                     •   Turbo charged 
                  
                 Fuel type 
                     •   gas fuels        
                                     
   -natural gas 
                                     
   -gasification (pirolysis) 
                                     
   -biogas, waste gas 
                                     
   -other 
                     •   liquid fuels     
                                     
   crude oil fractions (distillation fuels) 
                                             •    Crude-oil (Diesel fuel) 
                                             •    Benzine  
                                             •    Kerosene (JET-A) 
                                             •    Heavy (ends) oils, etc 
                                     
   Renewable fuels 
                                             •    Rape-, sunflower-seed oil, RME 
                                             •    Alcohols, Bioethanole, etc 
                                     
   Other 
                  
                 Air-fuel mixing methods 
                                     
   Internal (CIE, GDI (SIE)) 
                                     
   External (SIE) 
                                                                                                                         
                                                                     
                 Control methods 
                     •   qualitative (SIE) 
                     •   quantitative (CIE, GDI (SIE)) 
                  
                 Combustion chamber design 
                     •   single open combustion chamber 
                     •   divided combustion chamber 
                                     
   swirl chamber systems 
                                     
   prechamber systems 
                  
                 Start of Combustion 
                     •   External energy (Spark) 
                     •   Compression 
                     •   Hot Spot 
                  
                                           Basic principals of mechanical construction 
                  
                 Arrangement of cylinders 
                     •   in line arrangement 
                     •   V arrangement 
                     •   opposed cylinder engine 
                     •   radial type engine 
                  
                  
                 Fluid inlet-outlet control 
                     •   side valve (SV) arrangement  
                     •   overhead valve (OHV)  arrangement  
                     •   overhead camshaft (OHC)  arrangement 
                  
                 cooling system 
                     •   air cooling 
                     •   water cooling 
                  
                                                                                                                         
                                                         
              Ideal cycles. 
               
              To produce mechanical power from heat power, a cycle process is needed. 
               
              Carnot cycle would be ideal, but there is no machine which is working according to the Carnot 
              cycle. 
               
              At the Carnot cycle: 
                                                                                                  
               
              Where: 
              Process 1 to 2 - isentropic expansion 
              Process 2 to 3 is isothermal heat rejection 
              Process 3 to 4 is isentropic compression 
              Process 4 to 1 is isothermal heat supply 
               
              Efficiency of the cycle: 
                  −∑W ∑Q (T−T)⋅(s −s )                  T
              ηη =       =      =   1   2   B   A  =1− 2  
              ηη    Q       Q        T ⋅(s −s )         T
                     1       1        1  B    A          1