Related by context. Frequent words. (Click for all words.) 57 spark ignition 56 combustor 53 stoichiometric 52 electrohydraulic 52 combustion 52 airflows 51 conventional internal combustion 51 compression ignition 51 combustion engine 50 Ti VCT 50 nitrogen oxide NOx emissions 50 feedwater 49 backpressure 49 coolant temperature 49 ionisation 49 electrochemical reaction 49 hydroxyl radicals 49 laminar flow 49 adiabatic 48 scramjet engine 48 electrolyser 48 combustion chamber 48 ionizer 48 electro hydraulic 48 twin turbochargers 48 solenoid valve 48 ramjet 48 NOx 48 hydraulic pump 48 tropospheric 48 combustion gases 48 variable valve 48 cylinder deactivation 47 induction motors 47 2kW 47 gearshifts 47 hydrologic cycle 47 sorption 47 oxidizers 47 piezo electric 47 venturi 47 cryogenic temperatures 47 gaseous emissions 47 RoCE 47 oxidizer 47 fuel injector 46 millivolts 46 thruster 46 desorption 46 ionize 46 turbo chargers 46 naturally aspirated engine 46 scramjets 46 Supercritical 46 gas recirculation 46 harmless nitrogen 46 turbofan engine 46 isothermal 46 gaseous hydrogen 46 subcritical 46 ionised 46 brushless motor 46 ambient temperature 46 servomotors 46 CVTs 46 reactant 46 thermo chemical 46 radiative forcing 46 reactants 45 exhaust gases 45 electric motor 45 N2O 45 Reverse osmosis 45 electrolyzer 45 nitrogen oxides NOx 45 SCR catalyst 45 PEM fuel 45 polymerisation 45 servomotor 45 glow plugs 45 centrifugal pump 45 economizer 45 ambient temperatures 45 irradiance 45 combustion chambers 45 H#O# 45 clutch pedal 45 #oC [002] 45 combusts 45 oxidant 45 cavitation 45 fluorocarbons 45 #,#-#,# rpm 45 CO -2 45 air conditioning compressor 45 ionic liquid 45 impellers 45 upper troposphere 45 sensor detects 45 fuser 45 degassing