Course code TraZ4057

Credit points 3

Automobile and Motor Theory I

Total Hours in Course120

Number of hours for lectures32

Number of hours for laboratory classes16

Independent study hours72

Date of course confirmation07.02.2017

Responsible UnitInstitute of Engineering and Energetics

Course developers

author prof.

Dainis Berjoza

Dr. sc. ing.

author Inženiertehnikas un enerģētikas institūts

Ruslans Šmigins

Dr. sc. ing.

Prior knowledge

Fizi2021, Physics I

Fizi2022, Physics II

TraZ4051, Ground Motor Vehicle Construction

Course abstract

The aim of the course is to get information about characteristics of theoretical cycles of internal combustion engines. They will study theoretical basics of real processes, parameters of engines, theory and calculations of engine’s mechanisms and systems, characteristics of engines, tendencies of engine’s development, thermodynamical calculation of internal combustion engine as well as engine testing methods and equipment, methods of calculating various resistance forces, power and traction forces balance and dynamic indicators, braking characteristics of the car.

Learning outcomes and their assessment

1. Knowledge - familiar with engine operating cycles, indicator charts, engine operating parameters and factors affecting them, as well as the progress of various processes in the engine – Test No. 1. Familiar with engine testing techniques, understanding the extraction of engine characteristics and being able to justify the obtained results – Test No. 2
2. Skills - knows the types of resistance, strength and power balance of the vehicle, the dynamics of running and braking and their interconnection - Test No 3. Capable of performing a thermodynamic calculation of the engine, defining and analyzing the reasons for changing of basic engine parameters, representing a variety of changes in engine work parameters in form of curves — Laboratory works.

3. Competence - capable of performing to experimentally determine gear ratios, air resistance, road tests and related calculations - laboratory works. Capable of perform car performance parameters calculations, to apply them in practice – homework, Test No 4.

Course Content(Calendar)

1. Ideal and mechanical cycles of engine operation. Indicator charts. Comparison of Otto and diesel charts. (3h)
2. Indicated and effective power, mechanical loss power, efficiency factors. Filling factor. Laboratory work No. 1. (3h)
3. Air change factor, its impact on power and economic performance. Laboratory work No. 2. (3h)
4. Method for preparing the fuel mixture in the diesel engine and the shape of combustion chambers. Compression process and compression grade. Laboratory work No. 3. (3h)
5. Combustion process in Otto engine. Combustion process in diesel engine. Expansion and exhaust process. Laboratory work No. 4. (3h)
Test No. 1: Engine operating cycles, working parameters, and their impact; factors influencing engine work parameters; analysis of processes.
6. Thermodynamic calculation of the engine. Calculation output data. Calculation of power and torque, heat balance. Laboratory work No. 5. (3h)
7. Engine testing methods and equipment. Methods for determining the indicated power. Determination of effective power. Laboratory work No. 6. (3h)
8. Engine adjustment characteristic and speed characteristic. The characteristic of the diesel engine at work with the governor. Laboratory work No. 7. (3h)
9. Engine load characteristics. Mechanical efficiency. Fuel consumption. Laboratory work No. 8. (3h)
Test No. 2: Testing methods and equipment for engines; experimental extraction, processing and presentation of engine working parameters; explanation of characteristics.
10. Motor - the source of energy for movement. Vehicle energy losses, efficiency. (3h)
11. Wheel radius. Vehicle speed. Force on driving wheels. (3h)
12. Wheel scrolling and rolling resistance. The coefficient of adhesion. (3h)
13. Different types of resistance of the car. (3h)
14. Parameters characterizing the traction dynamics of a car. Traction forces balance. Power balance. (3h)
15. Dynamic Characteristics of a Car. The dynamic factor of the car and the dynamics of running. (3h)
16. Vehicle braking parameters, calculation and experimental determination. (3h)

Test No. 3: Vehicle traction and power balance, running dynamics and braking parameters

Requirements for awarding credit points

Overall test without a grade.
Laboratory works created and defended, tests - written.

Description of the organization and tasks of students’ independent work

Preparation for tests and laboratory works.
3 homework is prepared and submitted in paper format. Accepted are homework with at least 60% of the tasks solved correctly.

Criteria for Evaluating Learning Outcomes

The study course could be counted if all previously mentioned requirements are realized.
Student can get a successful mark for test if at least 50% of the questions are answered correctly.

Compulsory reading

1. Šmigins R. Iekšdedzes motoru teorija. Jelgava: LLU, 2008. 179 lpp.
2. Šmigins R. Motoru izmēģināšana: Metodiskie norādījumi. Jelgava: LLU, 2008. 60 lpp.
3. Berjoza D. Automobiļu teorija. Metodiskie norādījumi kursa darba izstrādei, uzdevumi un laboratorijas darbi. Jelgava: LLU, 2007. 54 lpp.
4. Berjoza D. Automobiļu teorija. Mācību grāmata. Jelgava: LLU, 2008. 200 lpp.
5. Bonnick A. Automotive Science and Mathematics London, Routledge: 2011, 265 p.; ISBN: 978-0-7506-8522-1

6. Karnopp D. Vehicle Stability, California, USA: 2004, 331 p. ISBN: 0-8247-5711-4

Further reading

1. Двигатели внутреннего сгорания. Под ред. В.Н. Луканина. В 3 кн. Москва: Высшая школа, 1995.
2. Wong J.Y. Theory of Ground Vehicles. 3rd ed. Hoboken, New Jersey: John Willey & Sons, 2008. 560 p.

3. Renner G., Wimmer A. Kalkulation fur Kraftfahrzeugmeister. Deuchland: Europa- Lehrmittel, 2005. 176 S.


The study course is included in the compulsory part of the Bachelor’s study program “Agricultural Engineering”.