There are none. There are some things hard to understand and especially many deep spiritual truths, but no contradictions. Since Luke, like the rest of scripture is divinely inspired, God knew what He wanted written through the mind and pen of Luke. He did not forget as He went nor did He contradict what He said previously in other places.
One thing that is sometimes forgotten is that the New Testament, indeed the whole Bible is written for believers and for those seeking truth. If we believe that many things written in it are impossible due to our presuppositions then much of The Bible will be for us untrue. In such a case where we believe our ideas to be superior to God and His self-revelation then there will be masses, indeed mountains of contradictions.
The contradictions in this case will not, however be those in the text itself, but arising from our own attitude which is not subject and submitted to God's will.
12 Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God.13 Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.14 But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
See also Christian Responses at the bottom of sub-links
This describes how many contradictions are not contradictions but merely out of context quotations.
PROVISIONAL ANSWER: Certainly the author of both Luke and Acts are one and the same. Certainly there are differences in some details in the two books. It is not certain that these logically constitute contradictions if taken in context. Thus the question itself is somewhat of a leading question which assumes something which is not at all proven. Differences do not necessarily constitute contradiction. Details of these alleged contradictions would need to be provided to answer the question more fully.
Resolving Contradictions was created in 1978-03.
Contradictions Collapse was created on 1991-10-01.
Contradictions - album - was created on 1999-11-09.
A mass of contradictions would be wheere there are many things or thoughts that go against each other.
Enigmas. Contradictions.
Type your answer here... what are the apparent contradictions in machiavelli's recommendations about a princes being liberal
One of the contradictions of the progressive movement involved race. Black suffrage was a major a problem and was not covered enough in the movement.
Thid
A contradiction is a disagreement between two things. This could also be stated as an incompatibility between two things. Contradictions tend to be verbal or mental and not physical.
Value contradictions (such as equality and racism) indicate areas of tension, which are likely points of social change.
The Contradictions of Fair Hope - 2012 was released on: USA: 2012 USA: 14 January 2014 (video premiere)